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The Astronomy DSO list specifies which Deep Space Objects may be covered in the Astronomy event that year, and is roughly analogous to the Deep Sky Objects typically found in the rules for the Division B event Reach for the Stars. It is typically listed in section 3.c of the rules.

General Tips

The DSO list can seem daunting at first. A good strategy for learning them is to take personalized notes from various sources while including images for identification.

  • Categorize the DSOs by their types or stages in stellar evolution (e.g. Brown Dwarfs, Red Giants, White Dwarfs, Cepheid Variables, Supernova remnants, Globular Clusters). Take notes on each of these stages, as well as what makes them significant in the study of astronomy.
    • For example - a Type Ia Supernova can either be the result of collision of two white dwarfs or accretion of matter from a stellar companion (often reaching the Red Giant stage), and its mostly uniform brightness can help astronomers determine distance to distant galaxies using the distance modulus.
  • For each DSO, take notes on what makes it unique and significant. The Chandra X-ray Observatory posts videos at the start of the competition season that briefly explain each object's significance. The Chandra photo album and NASA's APOD are also good resources for images and information on DSOs. For Variable stars, AAVSO is a helpful resource.
  • Find photos (and light curves for variable stars) of the Deep Space Objects, as many as possible and across all wavelengths. Almost all tests include tasks to identify DSOs based on images or find all images of a certain DSO/category, and more difficult tests sometimes include more obscure images of the DSOs. Include the wavelength of light a certain image was taken in.
  • Take notes on miscellaneous information about each DSO, including, but not limited to: constellation, alternate names, magnitude, stellar classification, right ascension/declination, and color index.
  • Take practice tests. They can help reveal weaknesses in any notes on Deep Space Objects.
  • If certain information about a DSO is given (such as the the masses and the separation of the binary system), calculate the period. Use information in any pre-existing notes to calculate other values before the test, saving valuable time.

2020 DSOs

2020 DSOs
Name Images Constellation Magnitude Distance Coordinates External Links
Apparent Absolute Right Ascension Declination
SN UDS10Wil UDS10Wil.jpg UDS10Wil-1.png Cetus 10.5 Gly, 3.2 Gpc 02h 17m 46.3s -05° 15′ 24.00″
SN UDS10Wil is the furthest supernova so far of the type used to measure cosmic distances. It was discovered by the Hubble Space Telescope and was discovered as part of a three-year Hubble program that started in 2010 to survey faraway Type 1a supernovae known as the CANDELS survey.
NGC 2623 NGC 2623.jpg [[]] Cancer 13.36 250 Mly, 76.7 Mpc 08h 38m 24.1s +25° 45′ 16.70″
NGC 2623 is the result of a major collision and subsequent merger between two galaxies. The merger is going through late stages and is thought to eventually resemble what the Milky Way will look like when it collides with our neighboring galaxy, Andromeda in 4 billion years.
GRB 150101B GRB 150101B.jpg [[]] Virgo 1.7 Gly, 0.52 Gpc 12h 32m 04.96s −10° 56′ 00.7″ Chandra


GRB 150101B is a likely merger of 2 neutron stars 1.7 billion light years from Earth. It is fairly similar to GW170817, the first source shown to emit gravitational waves and light.
JKCS 041 JKCS 041.jpg [[]] Cetus ~9.9 Gly, ~ 3.04 Gpc 02h 26m 44s −04° 41′ 37″ Chandra
JKCS 041 is a group of galaxies about 9.9 billion light years. it is the farthest galaxy group from Earth discovered. It has a redshift of 1.9.
MACS J0717.5+3745 Macsj0717.jpg MACS J0717-dark.jpg Auriga 5.4 Gly, 1.7 Gpc 07h 17m 36.50s +37° 45′ 23″ Chandra
MACS J0717.5+3745 is a massive galaxy cluster where 4 galaxy subclusters are colliding.
MACS J1149.5+2223 Macsj1149-comp.jpg [[]] Leo Approximately 5 billion light-years 11h 49m 36.3s +22° 23′ 58.1″ Chandra

Frontier Fields

MACS J1149.5+2223 is a galaxy cluster which bends light from more distant objects due to its huge mass through gravitational lensing.
Bullet Cluster (1E 0657-56) Bullet-cluster.jpg Bullet cluster.jpg Carina 3.7 billions light-years, 1.141 Gpc 06h 58m 37.9s −55° 57′ 0″
The Bullet Cluster is a system of two colliding galaxy clusters. Most of its mass is concentrated around galaxies instead of gas, which could be evidence for the existence of dark matter.
H1821+643 H1821.png [[]] Draco 14.24 3.4 Gly, 1.0 Gpc 18h 21m 57.24s +64° 20′ 36.23″ Chandra


H1821+643 is a luminous quasar which has been used to search for the WHIM. At its core is one of the most massive black holes known.
GOODS-S 29323 Bhseeds 29323.jpg Bhseeds.jpg Fornax 13.2 Gly, 4.05 Gpc 03h 32m 28s –27° 48′ 30″ Chandra
GOODS-S 29323 is a direct collapse black hole seed candidate. It could support a model of SMBH formation which would allow them to form quickly in the early universe.
H2356-309 H2356 illustration.jpg H2356 spec.jpg Sculptor Approximately 2 billion light-years 23h 59m 07.9s -30° 37′ 41.00″ Chandra


H2356-309 is a blazar which was used to detect WHIM (in the form of an oxygen absorption line) in the Sculptor Wall.
152156.48+520238.5 152156.jpg [[]] Boötes Approximately 10.75 billion light-years 15h 21m 56.5s +52° 02′ 38.50″ Chandra
152156.48+520238.5 is a quasar which has similar properties to the quasar PHL 1811. The disk around it may be puffed up (from high accretion rates), causing it to be fainter in X-rays and have weak emission lines.
153714.26+271611.6 153714.jpg [[]] Corona Borealis Approximately 11.03 billion light-years 15h 37m 14.3s +27° 16′ 11.6″ Chandra
153714.26+271611.6 is a quasar similar to PHL 1811. Like 152156.48+520238.5, it has weak emission lines probably caused by a puffed-up accretion disk.
222256.11-094636.2 222256.jpg [[]] Aquarius Approximately 11.48 billion light-years 22h 22m 56.10s -09° 46′ 36.20″ Chandra
222256.11-094636.2 is a quasar similar to PHL 1811. Like 152156.48+520238.5, it has weak emission lines and weak X-ray emission, likely caused by a puffed-up disk.
PSS 0133+0400 [[]] [[]] Pisces Approximately 10.1 billion light-years 01h 31m 04.8s +03° 45′ 37.8″ Chandra
PSS 0133+0400 is a quasar which was used in a study to find out that the strength or amount of dark energy may be increasing.
PSS 0955+5940 [[]] [[]] Ursa Major Approximately 10.2 billion light-years 09h 51m 37.4s +59° 54′ 43.6″ Chandra
PSS 0955+5940 is a quasar which was used in the same study as PSS 0133+0400.
GW151226 [[]] [[]] Approximately 1.4 billion light-years n/a n/a LIGO
GW151226 was a Gravitational-Wave signal observed by the twin detectors of the Laser Interferometer Gravitational-Wave Observatory (LIGO) on December 26, 2015 at 03:38:53 UTC making it the second definitive observation of a merging binary black hole system detected by the LIGO Scientific Collaboration and Virgo Collaboration.
M87 Hubble M87.jpg Chandra M87.jpg Virgo 7.19 53.5 ± 1.6 Mly, 16.4 ± 0.5 Mpc 12h 30m 49.42338s +12° 23′ 28.0439″ Chandra
M87 is a nearby elliptical galaxy with an active galactic nucleus. The central SMBH of M87 was imaged by the Event Horizon Telescope as the first black hole to be imaged.
3C 273 3c273-optical.jpg 3c273-multi.jpg Virgo 12.9 2.443 Gly, 749 Mpc 12h 29m 06.7s +02° 03′ 09″ AAVSO


3C 273 is the most optically bright quasar, and also one of the closest, in our night sky. Along with 3C 48, it was the first object to be identified as what we now know to be quasars.

Previous DSO Lists

2019 DSOs
2019 DSOs
Name Images Constellation Magnitude Distance Coordinates External Links
Apparent Absolute Right Ascension Declination
NGC 5195 M51 NGC 5195.jpg Ngc5195 xray.jpg Canes Venatici 10.5 25 Mly, 7.7 Mpc 13h 29m 59.6s +47° 15′ 58″
A dwarf galaxy that is interacting with the Whirlpool Galaxy. Because of its interaction with the Whirlpool Galaxy, it is highly distorted. In the picture, the Whirlpool Galaxy is on the left and NGC 5195 is the smaller galaxy to the right.
IC 10 IC10.jpg Ic10 xray.jpg Cassiopeia 10.4 2.2 Mly, 660 kpc 00h 20m 17.3s +59° 18′ 14″
An irregular starburst galaxy featuring a large amount of Wolf-Rayet stars.
SPT 0346-52 Spt03461.jpg Spt0346 comp.jpg Horologium 12.7 billion light years 03h 46m 41.13s -52° 05' 02.11"
A starburst galaxy that resulted from a collision between two galaxies. It has one of the highest star formation rates of any galaxy.
M81/M82 M81.jpg M82.jpg Ursa Major 6.94 8.5 ± 1.3 Mly (2.6 ± 0.4 Mpc) 09h 55m 33.2s +69° 3′ 55″
M81, also known as "Bode's Galaxy", is a large spiral galaxy. It is the center of the M81 group. M82, also known as the "Cigar Galaxy", is a starburst galaxy in the same group as M81 (same region of sky).
ESO 137-001 Eso137.jpg Eso137xray.jpg Triangulum Australe Unknown apparent magnitude; apparent size 1.23 arcminutes × 0.55 arcminutes 220 million ly 16h 13m 27.305s −60° 45′ 50.59″
ESO 137-001 is a barred spiral galaxy. As the galaxy moves to the center of the Abell 3627 cluster at 7 million kilometers per hour, it is stripped by hot gas thus creating a 260,000 light-year long tail. The intergalactic gas in the Abell 3627 is 180 million degrees Fahrenheit which causes star formation in the tails.
SN 2014 Sn2014j.jpg Sn2014j-light.jpg Ursa Major n/a n/a 11,500,000 ly (3,500,000 pc) 9h 55m 42.217s 69° 40′ 26.56″
SN 2014J was a type-Ia supernova in Messier 82 (the 'Cigar Galaxy', M82) discovered in mid-January 2014 by chance during an undergrad astronomy course at the University of London Observatory. It was the closest type-Ia supernova discovered for 42 years, and none have been closer as of 2018.
Phoenix Cluster Phoenix-cluster.jpg Phoenix w33.jpg Phoenix 5.7 billion light years 23h 44m 40.9s −42° 41′ 54″
The Phoenix Cluster (SPT-CL J2344-4243) is a massive, type I galaxy cluster in the Phoenix Constellation.It is one of the most massive galaxy clusters known, with the mass on the order of 2×1015 M☉. Most of the mass of the Phoenix Cluster is in the form of dark matter and its intracluster medium. The vast stellar halo of the Phoenix Cluster central galaxy extends to over 1.1 million light years from the center, making it one of the largest galaxies known. It is 22 times the diameter of our galaxy, and its starburst activity suggests that the galaxy is still growing larger. More X-Ray production than any other massive cluster.
NGC 4993 Ngc4993.gif Eso1733c.jpg Hydra 13.32 -20.85 44.1 Mpc (144 Mly) / 130.5 million light years 13h 09m 47.7s −23° 23′ 02″
NGC 4993 is the site of the first astronomical event detected in both electromagnetic and gravitational radiation, the collision of two neutron stars, an event that provided direct confirmation that binary neutron star collisions produce short gamma-ray bursts.
47 Tucanae 47 Tucanae.jpg 47tuc x9.jpg Tucana +4.09 4.0 ± 0.35 kpc (13,000 ± 1,100 ly) 00h 24m 05.67s –72° 04′ 52.6″
47 Tucanae, 47 Tuc (or NGC 104) is a globular cluster that is 120 light years across. 47 Tuc can be seen with the naked eye, holding the position of second brightest globular cluster after Omega Centauri. X9 (closest orbit between star and black hole, containing a white dwarf and a stellar-mass black hole in orbit).
Chandra Deep Field South Chandra deep field.jpg Cdfs bh.jpg Fornax n/a n/a n/a 3h 32m 28.0s −27° 48′ 30″ n/a
The Chandra Deep Field Survey South is a photograph taken for over 8 million seconds exposure by the Chandra Deep Field Telescope. It contains at least 5,000 black holes, which makes it a topic of interest for astronomy.
Cen A Centaurus a.jpg Centarus a.jpg Centaurus 6.84 13h 25m 27.6s −43° 01′ 09″
Either an elliptical or lenticular galaxy. One of the closest and brightest radio galaxies to Earth, and is a starburst galaxy. contains a black hole in the middle roughly at 55 million stellar masses. By taking radio observations of the jet separated by a decade, astronomers have determined that the inner parts of the jet are moving at about half of the speed of light. X-rays are produced farther out as the jet collides with surrounding gases resulting in the creation of highly energetic particles. The X-ray jets of Centaurus A are thousands of light-years long, while the radio jets are over a million light-years long.
M100 M100.jpg Messier-100.jpg Coma Berenices 9.5 12h 22m 54.9s +15° 49′ 21″ 55 Mly
Messier 100 is a Grand Design intermediate spiral galaxy, which also is classified as a starburst galaxy. It is located in the Virgo cluster. The galaxy is estimated to contain about 400 billion stars.
Abell 400/3C 75 A400 comp.jpg 3c75.jpeg Cetus 02h 57m 38.6s +06° 02′ 00″ 100 Mpc (326 Mly)
Abell 400 is a galaxy cluster which contains the galaxy NGC 1128 with two supermassive black holes (3C 75) spiraling towards merger. The black holes are an estimated 25,000 light years apart, and thus will take millions of years to collide. Should the two supermassive black holes merge, they will form a single super-supermassive black hole. 3C-75, the system containing the black holes, has four radio jets (two from each accreting black hole). It is travelling at 1200 kilometers per second through the cluster plasma, causing the jets to be swept back.
Antennae Galaxies / NGC 4038 & NGC 4039 Antennae galaxy.jpg Antennae galaxies.jpg Corvus 11.2 / 11.1 12h 01m 53.0s / 12h 01m 53.6s −18° 52′ 10″ / −18° 53′ 11″ 45 Mly / 65 Mly
NGC 4038/NGC 4039 are a pair of interracting galaxies currently undergoing Starburst, in which the collision of gas and dust are influencing accelerated star formation. The nuclei of galaxies are expected to eventually form a single larger galaxy.
Sagittarius A* Saggy a.jpg Saggy a real.jpg Sagittarius n/a n/a 17h 45m 40.0409s −29° 0′ 28.118″ 7,860 ± 140 ± 40 pc
Sgr A is a complex radio source in the center of the Milky Way galaxy. It is shrouded at optical wavelengths by hydrogen clouds, however can be detected due to it's large compact radio signature. Consists of three components: Sagittarius A East, a supernova remnant, Sagittarius A West, a spiral structure, and a complex radio signature in the center Sagittarius A*, which is assumed to be a supermassive black hole.
2018 DSOs
2018 DSOs
Name Images Constellation Magnitude Distance Coordinates External Links
Apparent Absolute Right Ascension Declination
AG Carinae AG Carinae.png AG Car Lightcurve AAVSO.png Carina 6.96 ~-8 (visible band) 6000 parsecs 10h 56m 11.58s -60° 27’ 12.8056" SIMBAD AAVSO
One of the brightest stars in the Milky Way, surrounded by a nebula. Apparent brightness can vary drastically between 5.7 and 8.3. This star is considered in transition from a blue supergiant to a WR-star.
Alpha Orionis Betelgeuse collision.jpg Betelgeuse2.png Orion 0.2-1.2 Absolute ~643 ly 05h 55m 10.3053s +07° 24' 25.426" AAVSO, Wikipedia
More commonly known as Betelgeuse, this semi-regular (SRc) pulsating red supergiant will likely explode as a type II supernova within the next million years.
ASASSN-15lh ASASSN-15lh location.jpg Hypernova ASASSN-15lh.jpg Indus 16.9 -23.5 (ultraviolet band) 1,171 megaparsecs 22h 2m 15.45s -61° 39’ 34.64” External Links
Supernova detected by the All Sky Automated Survey. It is either the most luminous type I supernova ever discovered, called a hypernova, or a tidal disruption event.
Circinus X-1 Image 1 Image 2 N/A Apparent Absolute Distance Right Ascension Declination External Links
Neutron star orbiting a conventional super-massive star.
DEM L241 Image 1 Image 2 Constellation Apparent Absolute Distance Right Ascension Declination [1]
Description of the DSO, important characteristics, etc.
Geminga GemingaArt.jpg GemingaXRay2.jpg Gemini Apparent Absolute 815 ly 06h 33m 54.15s +17° 46′ 12.9″ [2]
Geminga is likely a decaying core of a Type II Supernova. It is highly visible in the gamma-ray spectrum.
HR 5171 A Image 1 Image 2 Constellation Apparent Absolute Distance Right Ascension Declination External Links
Description of the DSO, important characteristics, etc.
IC 443 Image 1 Image 2 Gemini, near Eta Geminorum Apparent Absolute 5000 ly, 1.5 kpc 06h 17m 13s +22° 31′ 05′′ External Links
IC 443 is a remnant of a supernova that likely occurred 3000-30,000 years ago. It is one of the best-studied cases of a supernova remnant interacting with the surrounding molecular clouds.
M82 X-2 Image 1 Image 2 Ursa Major Apparent Absolute 12 million ly, 3.5 million pc 09h 55m 51.0s 69° 40′ 45″ External Links
M-82 X-2, an X-ray pulsar in the Messier 82 galaxy, is noted for being an ultra luminous X-ray source (ULX), shining around 100x brighter than predicted. It is part of a binary system, where it revolves around the larger star about once every 2.5 days. It rotates about once every 1.37 seconds. It was uncovered by NuSTAR and verified by the Chandra and Swift spacecraft.
NGC 6357 Image 1 Image 2 Scorpius Apparent Absolute ~5500 ly, ~1680 pc 17h 25m 34.2s −34° 23′ 12" External Links
NGC 6357 is a diffuse nebula. It is also named the War and Peace nebula, because infrared pictures appear to depict a dove and a skull, and the Lobster nebula. It includes the Pismis cluster, containing a number of massive stars, as well as two young stellar clusters, G353.2+0.7 and G353.1+0.6. It is one of the most important sites of massive star formation in the Milky Way.
NGC 7822 Image 1 Image 2 Cepheus Apparent Absolute 2900 ly, 900 pc 00h 01m 08.58s +67° 25′ 17.0″ External Links
NGC 7822 is a star forming region that is believed to be relatively young. It contains the star BD+66 1673, one of the hottest stars discovered within 1 kpn of the Sun, and is noted for its elephant trunk-shaped pillars of creation. Description of the DSO, important characteristics, etc.
PSR B0355+54 Image 1 Image 2 Constellation Apparent Absolute Distance Right Ascension Declination [3]
Description of the DSO, important characteristics, etc.
RCW 103 Image 1 Image 2 Norma Apparent Absolute 10110 to 10760 ly, 3100 to 3300 pc 16h 17m 30s -51° 02′ External Links
RCW 103 is a supernova remnant containing the neutron star 1E 161348-5055 at its center. This neutron star is notable for having a spin period much longer than other observed pulsars and much longer than what is predicted based on its age.
S Doradus SDoradus light curve .png SDoradus light curve full.png Dorado 8.6-11.5 -10.0 169000 ly, 51.8 kpc 05h 18m 14.3550s −69° 15′ 01.151″ External Links
First observed in 1897, S Dor is a Luminous Blue Variable (LBV) located in the Large Magellanic Cloud (LMC). It is also the brightest member of NGC 1910, an open cluster. An entire class of variable stars are named after this DSO, which have the unusual characteristic of short-term microvariations superimposed over long-term macrovariations.
SN 1987A Image 1 Image 2 Dorado Peaks around +2.9 Absolute 168,000 ly, 51.4 kpc 05h 35m 28.03s −69° 16′ 11.79″ External Links
The closest observed supernova since SN 1604, its light reached the Earth 23 February 1987. It was the first opportunity for astronomers to study the development of a supernova and learn more about core-collapse supernovae. Additionally, it detected gamma-ray radiation that proved that the post-explosion glow is radioactive. This was also the first supernova where astronomers were able to directly observe emitted neutrinos.
SN W49B Image 1 Image 2 Aquila Apparent Absolute 33,000 ly, 10 kpc 19h 11m 09s +09° 06′ 24″ Chandra Chandra (picture)
One of the most luminous SNRs in the galaxy at gamma-ray wavelengths, SN W49B also shows Cr and Mn x-ray emissions and has asymmetrically distributed Fe and Ni. It is thought to have left a black hole at the center - possibly the most recent black hole formed in the Milky Way.
2017 DSOs
2017 DSOs
Name Images Constellation Magnitude Distance Coordinates External Links
Apparent Absolute Right Ascension Declination
Henize 2-428 Henize2428.jpg Henize2428 2.jpg Aquilla 19h 13m 05.239s +15° 46′ 39.80″
Heaviest known WD binary system ;Will eventually merge in 700 million years; Originally binary star system of two sun-like stars of equivalent mass; Total mass 1.8 M_sun; Nebula is asymmetric because of binary system at center instead of single star; The planetary nebula came from the outer later of the original star, from contraction/expansion during the Red Giant stages; Period is 4 hours; Emit gravitational waves resulting in loss of energy; Will eventually cause Type 1a supernova when they merge, absolute magnitude =/= -19.3 because of increased mass: will not be useful as standard candle.
Henize 3-1357 (Stingray Nebula) Stingray1.jpg Stingray2.jpg Ara 10.75 -3.0 18kly 17h 16m 21.071s −59° 29′ 23.64″ APOD NASA Gallery
Youngest known planetary nebula; Radius 0.02 pc (as large as 130 solar systems), separated by 0.3arcsec; Age 2650 yr, gases light up for no more than 40 yr; Core mass 0.59 M_sun; ionized mass (nebula mass) 0.2Msol; Star at the center was originally a asymptotic giant branch B1 supergiant, still evolving to WD; White dwarf has strong hydrogen rich Balmer lines; Luminosity 3000 L_sun.
HM Cancri (RX J0806.3+1527) RXstar.jpg Hmcancricurve.jpg Cancer 21.1 ~1600 ly 08h 06m 23.20s +15° 27' 30.20" Chandra
Period 321.5 seconds: shortest period known; proper motion 1.1mas/yr; separation 0.0005 A; 400,000 km/sec, approaching at 2.0ft/day and orbit decaying at 1.2 ms/yr; total mass of 1.18 M_sun assuming separation of 1.02 x 10 -6 arcseconds; Double WD system, releases gravitational wave; X-Ray binary; X-Rays originate from accretion flow crashing into magnetic poles of white dwarf.
J075141/J174140 (two objects) J075 J174 1.jpg J075 J174 2.jpg Monceros/Draco 07h 51m 41.20s/17h 41m 40.50s -01° 41' 20.90"/+65° 26' 38.70" Chandra
Binary system; white dwarf with a companion star; theoretically give off gravitational waves; Potentially may not create Type 1a Supernova, maybe a Type 1ax or .Ia Supernova, where detonation only on surface of star.
M15 M15 2.jpg M15 1.jpg Pegasus 6.2 -9.2 ~33,600 ly 21h 29m 58.33s +12° 10′ 01.2″ Messier Catalogue UAlabama APOD
M15 is one of the oldest known and closest globular clusters to Earth. It is potentially one of the densest clusters known, containing over 100,000 stars with 112 variables, 8 pulsars, and 1 double neutron star system which gives off X-rays. It contains a planetary nebula called Pease 1, which shows that stellar evolution still takes place in globular clusters.
NGC 1846 NGC1846 1.jpg NGC1846 3.jpg Dorado 160,000ly 05h 07m 33s -67° 27' 41" NASA
NGC 1846 is a globular cluster with an unusual HR diagram: there are two turn-off points. Stars in a globular clusters form at the same time, meaning that the after the turnoff point there should be few stars. There are two different populations of stars in the clusters, with calculated age difference of around 300 million years, which is suspected to be caused by a merge of 2 globular clusters. Additionally, there is a potential planetary nebula within the cluster.
NGC 2392 (Eskimo Nebula) NGC2392 1.jpg NGC2392 2.jpg Gemini 10.1 0.4 ~3000 ly 07h 29m 10.7669s +20° 54′ 42.488″ APOD
NGC 2392 is a double shell planetary nebula often called the Eskimo nebula. The rings of the nebula are formed by the collision of fast and slow moving gases. The nebula is about 10,000 years old, and will last about another 50,000 years before it cannot be seen. The high X-ray emission could be potentially due to an unseen companion star. Notable features include strong OIII lines and weak Hα lines.
NGC 2440 NGC2440 1.jpg NGC2440 2.jpg Puppis 9.4 07h 41m 54.91s −18° 12′ 29.7″ NASA APOD Chandra
NGC 2440 is a planetary nebula containing the hottest known white dwarf, HD62166. The white dwarf itself has a temperature of 200,000K, and is surrounded by cooling gas. Most light is emitted in UV, ionizing the surrounding material. Its multipolar structure could potentially be caused by the shedding of mass in different locations or precession.
Omicron Ceti (Mira) Star mira full.jpg Mira illustration.jpg Cetus 3.04 -5.04 to -5.16 ~420 ly 02h 19m 20.79210s –02° 58′ 39.4956″ Chandra NASA Science News
Mira is the prototype for Mira variables, which are red giants that oscillate over long periods. It is a binary star system, with Mira A the red giant on the asymptotic giant branch that is losing mass and Mira B the white dwarf that is accreting mass. Historically, it was the first non-supernova variable star discovered. Mira A(?) is not spherical, rather it is egg shaped due to the non-radial nature of its pulsations. Additionally, it exhibits a bow shock, which was only recently discovered due to the need for high tech observatories in UV. Mira has been observed in almost all frequencies, each having seemingly different shapes and giving specific information about the star.
Sirius A & B Sirius 1.jpg Sirius 2.jpg Canis Major -1.46 1.42 8.6ly 06h 45m 09s −16° 42′ Chandra APOD
Sirius A and B are collectively the brightest star in the sky. Sirius A is a type A1 star, and Sirius B is a white dwarf. Sirius B was originally a bright blue star, which then shed its outer layers and became a white dwarf with broad hydrogen absorption lines. Their separation is 20 AU. Sirius A emits more radiation in the visible spectrum, while Sirius B emits more radiation in the X-ray spectrum.
SN2011fe SN2011fe 1.jpg SN2011fe 2.jpg Ursa Major +9.9 -19 21 Mly 14h 03m 05.8s +54° 16′ 25″ NASA AAVSO
SN 2011fe is the youngest Type 1a Supernova discovered. Discovered by the Palomar Transient Factory in 2011, it was used to test predictions and models of Type 1a supernovae. The progenitor was a carbon-oxygen white dwarf with a star no larger than the Sun. As with many type 1a supernovae, a large amount of energy was emitted through the decay of Ni-56. The location of the supernova was in the Pinwheel galaxy (M101).
SNR 0509-67.5 SNR0509 1.jpg SNR0509 2.jpg Dorado ~52,000 pc/160 kly 05.01h 09.01m 31.01s −67.01° 31.01′ 18.2″ Chandra APOD
SNR 0509-67.5 is a Type 1a supernova remnant found in the Large Magellanic Cloud. It was mostly likely a double degenerate system given the lack of companions in the vicinity. There is little doubt as to where it was a Type 1a supernovae, due to the silicon found after the explosion. It was observed through a light echo where light reflects off interstellar dust, delaying its arrival by 400 years. The outer ring is gas that has been shocked and heated by the supernova., expanding at 11,000 mph.
G1.9+0.3 G19 1.jpg G19 2.jpg Sagittarius ~7665 pcs 17h 48m 45.4s -27° 10' 06" Chandra
SNR G1.9+0.3 was most likely a double degenerate progenitor supernova. It is only 110 years old, the youngest Type Ia Supernova in the Milky Way. While the light would have reached the Earth in the 19th century, interstellar dust obscured it. However, the X-rays and radio waves were able to penetrate the gas. The remnant has a very asymmetric pattern, and exhibits synchrotron radiation (charged particles traveling in a curved path).
SS Cygni Image 1102-ss-cygni-binary-star.jpg SSCygni.png Cygnus 7.7-12.4 2.42-7.12 114 pcs 21h 42m 42.804s 43° 35' 09.88" AAVSO Chandra
A recurrent nova with a very massive white dwarf and a red dwarf-type star cooler than our sun. Often classified as U Geminorum type dwarf nova. SS Cygni is commonly thought of as the prototype dwarf nova. There are three parts to the system, the two stars and the accretion disk. The accretion disk pulsates in brightness, causing its variability. The period of the system is 6.5 hours, with outbursts every 7-8 weeks.
Tycho's SNR TychoSNR.jpg Tychos 2.jpg Cassiopeia ~9000 ly 00h 25m 17s 64° 08' 37" Chandra NASA APOD
A Type 1a supernova remnant that was observed in 1572 and later studied by Tycho Brahe. It remains one of the few supernovae visible to the naked eye. It was detected again using radio waves in 1952, and found that a G0-G2 star was the companion to the white dwarf progenitor. The companion star was most likely around 1.4 solar masses.
2016 DSOs
2016 DSOs
Name Images Constellation Magnitude Distance Coordinates External Links
Apparent Absolute Right Ascension Declination
2MASS J22282889-431026 2MASSJ22282889-431026 1.jpg [[]] Grus 35 ly, 10.6 pc 22h 28m 28.894s -43° 10′ 26.27″
2MASS J22282889-4310262 is a brown dwarf used to study windstorms on brown dwarfs. These investigations were the first to observe the variability in weather on brown dwarfs at different altitudes. It was discovered by the Hubble Space Telescope and the Spitzer Space Telescope in 2013.
51 Pegasi b 51 Pegasi b 1.jpg [[]] Pegasus 5.49 50.9 ly, 14.7 pc 22h 57m 28.0s +20° 46′ 08″
51 Pegasi b (also known as Bellerophon and Dimidium) was the first exoplanet found orbiting a main-sequence star.
55 Cancri 55 Cancri 1.jpg [[]] Cancer 40.3 ly 08h 52m 35.81s +28° 19′ 51.0″
AB Aurigae [[]] [[]] Auriga ~470 ly 04h 55m 45.8445s +30° 33′ 04.292″
Barnard 68 [[]] [[]] Ophiuchus 500 ly 17h 22m 38.2s -23° 49′ 34
GD 165 [[]] [[]] Bootes ~103 ly 14h 24m 39.144s +09° 17′ 13.98
HAT-P-11b [[]] [[]] Cygnus 122 ly 19h 50m 50.25s +48° 04′ 51.1″
HD 95086 [[]] [[]] Carina 296 ly 10h 57m 03s -68° 40′ 02″
HD 106906b [[]] [[]] Crux 300 ly 12h 17m 53.0s −54° 01′ 28″
HR 8799 HR 8799.jpg [[]] Pegasus 129 ly 23h 07m 28.7150s +21° 08′ 03.302"
Kepler-186 [[]] [[]] Cygnus 492 ly 19h 54m 36.651s +43° 57′ 18.06″
M42 [[]] [[]] Orion 1344 ly 05h 35m 17.3s −05° 23′ 28″
HR 8799 T Tauri 1.jpg [[]] Taurus ~600 ly 04h 21m 59.43445s +19° 32′ 06.4182″
WASP-18b [[]] [[]] Phoenix 325 ly 01h 37m 24.95s –45° 40′ 40.8″
WASP-43b [[]] [[]] Sextans ~80 pc 10h 19m 38s −09° 48′ 23″
WISE 0855-0714 [[]] [[]] Hydra 7.53 ly 08h 55m 10.83s –07° 14′ 42.5″
2015 DSOs
2015 DSOs
Name Images Constellation Magnitude Distance Coordinates External Links
FU Orionis FU Orionis 1.jpg Orion Apparent: Absolute: ~1300 ly Right Ascension: 05h 45m 22.362s; Declination: +09° 04′ 12.31″ AAVSO
TW Hya TW Hya 1.jpg Hydra Apparent: Absolute: 176 ly Right Ascension: 11h 01m 52s; Declination: −34° 42′ 17″
2M1207 2M1207 1.jpg Centaurus Apparent: Absolute: 172 ly Right Ascension: 12h 07m 33.47s; Declination: −39° 32′ 54.0″
CoRoT-2 CoRoT-2.jpeg Aquila Apparent: Absolute: 930 ly Right Ascension: 19h 27m 06.496s; Declination: +01° 23′ 01.38″
HD 209458b HD 209458b.jpg Pegasus Apparent: Absolute: 154 ly Right Ascension: 22h 03m 10.8s; Declination: +18° 53′ 04″
HD 189733b HD 189733b.jpg Vulpecula Apparent: Absolute: 63.4 ly Right Ascension: 20h 00m 43.71s; Declination: +22° 42′ 39.1″
Kepler-7b Kepler-7b.png Lyra Apparent: Absolute: ~3400 ly Right Ascension: 19h 14m 19.6s; Declination: +41° 5′ 23.3″
GJ 1214b GJ 1214b.jpg Ophiuchus Apparent: Absolute: 42 ly Right Ascension: 17h 15m 18.942s; Declination: +04° 57′ 49.69″
Beta Pictoris Beta Pictoris.jpg Pictor Apparent: Absolute: 63.4 ly Right Ascension: 05h 47m 17.1s; Declination: −51° 03′ 59″
Fomalhaut Fomalhaut.jpg Piscis Austrinus Apparent: Absolute: 25.13 ly Right Ascension: 22h 57m 39.0465s; Declination: −29° 37′ 20.050″
HR 8799 HR 8799.jpg Pegasus Apparent: Absolute: 129 ly Right Ascension: 23h 07m 28.7150s; Declination: +21° 08′ 03.302″
WISE 1049-5319 WISE 1049-5319.jpg Vela Apparent: Absolute: 6.6 ly Right Ascension: 10h 49m 18.723s; Declination: −53° 19′ 09.86″
Gliese 229B Gliese 229B.jpg Lepus Apparent: Absolute: 18.8 ly Right Ascension: 06h 10m 34.6154s; Declination: −21° 51′ 52.715″
LP 944-20 LP 944-20.jpg Fornax Apparent: Absolute: 20.9 ly Right Ascension: 03h 39m 35.220s; Declination: –35° 25′ 44.09″
N159 N159.jpg Dorado Apparent: Absolute: 170000 ly Right Ascension: 05h 40m 04.2s; Declination: –69° 44′ 43″
M20 M20.jpg Sagittarius Apparent: Absolute: 5200 ly Right Ascension: 18h 02m 23s; Declination: −23° 01′ 48″
2014 DSOs
2014 DSOs
Name Images Constellation Magnitude Distance Coordinates External Links
Mira (Omicron Ceti) Star mira full.jpg Mira illustration.jpg Cetus Apparent: 2.0 to 10.1 Absolute: ~-2.5 to 4.7 ~420 ly Right Ascension: 02h 19m 20.70s; Declination: -02° 58' 39.51" Chandra NASA Science News
Mira is the prototype for Mira variables, which are red giants that oscillate over long periods. It is a binary star system, with Mira A the red giant that is losing mass and Mira B the white dwarf that is accreting mass.
W49B W49b 1680.jpg W49b w44.jpeg Aquila Apparent: ~26,000 light years Right Ascension: 19h 11m 07s Declination: +09° 06' 00" Chandra
W49B is an SNR that is theorized to have a distorted shape and a black hole from the explosion that created the remnant. It may be the most recent black hole formed in the Milky Way.
Tycho's SNR (SN 1572) TychoSNR.jpg Tycho.jpg Cassiopeia Peak Apparent: -4 ~9000 ly Right Ascension: 00h 25m 17s; Declination: +64° 08' 37" Chandra NASA APOD
A Type 1a supernova remnant that burst in early November 1572 and was later studied by Tycho Brahe.
Vela SNR VelaSNR.jpg Vela.jpg Vela Apparent: 12 ~800 ly Right Ascension: 08h 35m 20.66s Declination: -45° 10' 35.2" APOD
The closest known supernova remnant to us with a notable pulsar and neighboring nebulae. Contains NGC 2736 or the Pencil Nebula, which is thought to have formed from part of the shock wave of the Vela SNR
G1.9+0.3 27949913 640.jpg H-398-2pan2 B radio.jpg Sagittarius Apparent: ~28,000 ly Right Ascension: 17h 48m 45s Declination: -27° 10' 00" Chandra NASA
Possibly the most recent supernovae, specifically Type Ia, in the Milky Way. It has an extremely asymmetric pattern. Explosion was likely highly non-uniform and unusually energetic.
Eta Carinae EtaCarinae.jpg New eta carinae.jpg Carina Apparent: -0.8 to 7.9 ~7,500 ly Right Ascension:10h 45m 03.591s Declination:−59° 41′ 04.26″ Chandra APOD
A hypergiant with a smaller companion. Massive supernova, very bright. It has a chance of exploding at any time, and will be so bright that it rivals the moon.
SS Cygni Image 1102-ss-cygni-binary-star.jpg SSCygni.png Cygnus Apparent: 7.7-12.4 370 ly Right Ascension: 21h 42m 42.804s Declination: 43° 35' 09.88" AAVSO Chandra
A recurrent nova with a very massive white dwarf and a red dwarf-type star cooler than our sun. Often classified as U Geminorum type dwarf nova.
T Tauri TTauri.jpg T Tauri 2MASS.jpg Taurus Apparent: 9.3-14 462 ly Right Ascension: 04h 21m 59.43s; Declination: +19° 32′ 06.42″ NASA APOD Universe Today
T Tauri is the prototype for T Tauri stars, which are the stars in the life stage between protostar and main sequence. there is a nebula located close to the star called Hind's Variable Nebula, which changes in luminosity as T Tauri varies.
GRS 1915+105 GRS1915+105 VLA.jpg Grs.jpg Aquila Apparent: 40,000 ly Right Ascension: 19h 15m 11.60s Declination: +10° 56' 44.00 Chandra
GRS 1915+105 is an x-ray binary star system containing a regular star and a black hole. It is one of the heaviest stellar black holes so far known in the Milky Way and has a self-regulating black hole.
47 Tucanae 47tuc salt.jpg 47Tucanae.PNG Tucana Apparent: 4.91 16,700 ly Right Ascension: 00h 24m 05.67s Declination: –72° 04′ 52.6″ Chandra APOD APOD
47 Tucanae is the second brightest globular cluster after Omega Centauri and one of the most massive globular clusters in the galaxy.
The Trapezium Orion1.jpg Trapcol.jpg Orion Apparent: 4 1,600 ly Right Ascension: 05h 35.4m Declination: −05° 27′ Chandra APOD APOD
The Trapezium is a relatively young open cluster in the heart o the Orion Nebula.
T Pyxidis 250px-Tpyx hst big.jpg TPyxidis.jpg Pyxis Apparent: 6.4-15.5 15,600 ly Right Ascension: 09h 04m 41.50s Declination: −32° 22′ 47.5″ AAVSO NASA APOD
T Pyxidis is a recurrent nova and nova remnant containing a sun-like star and a white dwarf. It is now close to the Chandrasekhar limit and might soon explode as a type 1a supernova.
Abell 30 A30 1680.jpg A30 w44.jpg Cancer Apparent: 15.6 5,500 ly Right Ascension: 08h 46m 53.50s Declination: +17° 52' 45.40" Chandra
Abell 30 is a planetary nebula in a special, rarely-seen phase of evolution. The evolution of A30 stalled and then started up again, so the planetary nebula was reborn.
RX J0806.3+1527 (HM Cnc) RXstar.jpg RXJ0806.PNG Cancer Apparent: 21.1 ~1600 ly Right Ascension: 08h 06m 23.20s; Declination: +15° 27' 30.20" Chandra
An x-ray binary system composed of two white dwarves that are rapidly orbiting each other. Their orbits are slowly getting closer, and the stars will eventually collide. Since they are faint, they are being observed by x-ray emissions.
V1647 Ori V1647.jpg Nasa ori star.jpg Orion Apparent: 1,300 ly Right Ascension: 05h 46m 13.10s Declination: -00° 06' 05.00" Chandra NASA
V1647 Ori is a FU Orionis variable star, a low-mass protostar still partly surrounded by its birth cloud. It is spinning as fast as it can without ripping itself to pieces.
V1 HV1-anim-500-22.gif V1.jpg Andromeda Apparent: 2.5 million ly Right Ascension: 00h 41m 27s Declination: 00h 41m 27s Hubblesite NASA
A Cepheid variable star in the Andromeda galaxy that began Hubble's discovery of the expansion of the universe by showing that the Andromeda galaxy was not part of our galaxy.
NGC 1846 1846.jpg NGC1846.PNG Doradus Apparent: 11.3 ~160,000 ly Right Ascension: 05h 07m 35.25s Declination: -67° 27' 38.9" Hubblesite NASA
NGC 1846 is a globular cluster located in the outer halo of the LMC. The most intriguing object is a faint green planetary nebula, and it doesn't seem to belong in the cluster.
NGC 3132 NGC 3132.jpg NGC3132 Master1.jpg Vela Apparent: 9.87 ~2,000 ly Right Ascension: 10h 07m 01.7640s Declination: −40° 26′ 11.060″ APOD APOD
NGC 3132 is a planetary nebula. There are two stars in the nebula, one of which is a white dwarf.
2013 DSOs
2013 DSOs
Name Images Constellation Magnitude Distance Coordinates External Links
Cassiopeia A Cassiopeia A.jpg CasAComposite.jpg Cassiopeia Apparent: Peak=~6 ~11,000 ly Right Ascension: 23h 23m 26.7s ; Declination: +58° 49' 3.00" Chandra
Cassiopeia A is the youngest supernova remnant in the Milky Way Galaxy.
IGR J17091 IGR J17091.jpg Igr one.jpg Scorpius Apparent: ~28,000 ly Right Ascension: 17h 09m 7.92s; Declination: -36° 24' 25.20" Chandra
IGR J17091 has the highest ever known wind speed at 20 million miles per hour, which is only 3% of the speed of light.
NGC 6888/ WR 136 NGC 6888.jpg WR 136 and NGC 6888.jpg Cygnus Apparent: +7.4 ~5,000 ly Right Ascension: 20h 12m 35.00s; Declination: +38° 26' 30.00" Chandra
NGC 6888, also known as the Crescent Nebula, was created the powerful winds coming off of the Star WR 136, or HD 192163.
PSR J0108-1431 J0108-1431.jpg J0108-1431 xray.jpg Cetus Apparent: peak: 27.8 ~770 ly Right Ascension: 01h 08m 08.30s; Declination: -14° 31' 48.50" Chandra, Neutron Star Physics Blog
PSR J0108-1431 is, by far, the nearest pulsar, or neutron star, to Earth.
Cygnus X-1 Cygnus x-1.jpg Binary cyg.jpg Cygnus Apparent: 8.95 Absolute: 6.5 ~6070 ly Right Ascension: 19h 58m 21.70s; Declination: +35° 12' 05.80" Chandra, NASA
Stephen Hawking lost a bet that Cynus X-1 did not contain a black hole; This black hole is 15 times the mass of the sun.
SXP 1062 Sxp1062 x-ray.jpg Sxp 1062.jpg Tucana Apparent: ~180,000 ly Right Ascension: 01h 29m 12.40s; Declination: -73° 32' 01.70" Chandra
There is evidence that there is a pulsar within this supernova remnant.
Messier Object M1 (Crab Nebula) Crab nebula m1.jpg CrabComposite.jpg Taurus Apparent: 8.4 ~6,500 ly Right Ascension: 05h 34m 32s; Declination: +22° 0.0' 52.00" Chandra, NASA
First observed in A.D. 1054, the Crab Nebula produces the equivalent of 100,000 suns in Energy and has a pulsar located in its center as well.
V838 Monocerotis V838 Mon NASA.jpg V838 Monocerotis.jpg Monoceros Apparent: 15.74 ~20,000 ly Right Ascension: 07h 04m 04.85s ; Declination: -03° 50' 50.1" NASA, NASA, Wikipedia
This object became 600,000 times more luminous than our Sun, for an instant, the brightest star in this galaxy, in January of 2002.
Delta Cep (Cephei) Deltacep.jpg Delta Cephei.jpg Cepheus Apparent: 3.5-4.4 887 ly Right Ascension: 22h 29m 10.26502s; Declination: +58° 24' 54.7139" AAVSO, Wikipedia
Delta Cep is located in a binary system, and is one of the closest Cepheid variable stars, with only Polaris being closer.
Alpha Orionis (Betelgeuse) Betelgeuse1.jpg Betelgeuse2.png Orion Apparent: 0.2-1.2 ~643 ly Right Ascension: 05h 55m 10.3053s; Declination: +07° 24' 25.426" AAVSO, Wikipedia
It will explode as a type II supernova within the next million years.
SN 2010JL SN2010JL1.jpg SN2010JL2.jpg Leo Apparent: ~160 million ly Right Ascension: 09h 42m 53.33s; Declination: +09° 29' 41.80" Chandra
It is the first evidence in X-rays of a supernova shock wave breaking through a cocoon of gas around the star. This discovery may help explain why some supernova explosions are more powerful than others.
NGC 3582 NGC3582-1.jpg NGC3582-2.jpg Carina Apparent: ~6000 ly Right Ascension: 11h 12m 12s; Declination: -61° 16′ 25" NASA APOD
A complex nebula where bright stars and interesting molecules are forming.
LHa115-N19 LHa115-N19-1.jpg LHa115-N19-2.jpg Tucana Apparent: ~196,000 ly Right Ascension: 0h 47m 31s; Declination: -73° 8.3' Chandra
This area is filled with ionized hydrogen gas and it is where many massive stars are expelling dust and gas through stellar winds.
Antares Antares-1.png Antares-2.jpg Scorpius Apparent: 0.96 ~550 ly Right Ascension: 16h 29m 24.45970s; Declination: -26° 25' 55.2094 Wikipedia
A red supergiant star in the Milky Way galaxy and the sixteenth brightest star in the nighttime sky.
Rho Ophiuchi Cloud complex Rhoophiuchicloud-1.jpg Rhoophiuchicloud-2.jpg Ophiuchus Apparent: ~460 ly Right Ascension: 16h 28m 06s; Declination: -24° 32.5′ Wikipedia, NASA APOD
One of the closest star-forming regions.
IC 1396 IC1396-1.jpg IC1396-2.jpg Cepheus Apparent: ~2,400 ly Right Ascension: 21h 38m 8.7s; Declination: +57° 26' 48" Wikipedia
One of the largest emission nebulae in the night sky. It contains "the Elephant's Trunk", a dark, dense globule in the nebula.
2012 DSOs
2012 DSO's
Name Images Constellation Magnitude Distance Coordinates External Links
Mira (Omicron Ceti) Star mira full.jpg Mira illustration.jpg Cetus Apparent: 2.0 to 10.1 ~420 ly Right Ascension: 02h 19m 20.70s; Declination: -02° 58' 39.51" Chandra NASA Science News
Mira is the prototype for Mira variables, which are red giants that oscillate over long periods.
SNR 0509-67.5 SNR0509675.jpg SNR 0509.jpg Dorado ~160,000 ly Right Ascension: 05h 09m 31.7s; Declination: -67° 31' 18.01” NASA APOD Chandra
A supernova remnant in the LMC (Large Magellanic Cloud). The explosion occurred 400 years ago for Earth observers.
CH Cyg CHcyg.jpg Cygnus Apparent: 5.6 to 10.5 ~815 ly Right Ascension: 19h 24m 33.07s; Declination: +50° 14' 29.13" Chandra AAVSO
CH Cyg is a symbiotic star system between a red giant and a white dwarf.
Kepler's SNR (SN 1604) KeplerSNR.jpg Ophiuchus ~13,000 ly Right Ascension: 17h 30m 40.80s; Declination: -21° 29' 11.00" Chandra NASA APOD
A Type 1a supernova remnant that was observed by Johannes Kepler in 1604.
Tycho's SNR (SN 1572) TychoSNR.jpg Cassiopeia ~9000 ly Right Ascension: 00h 25m 17s; Declination: +64° 08' 37" Chandra NASA APOD
A Type 1a supernova remnant that was observed in 1572 and later studied by Tycho Brahe.
Messier 15 (NGC 7078) M15 2.jpg M15 1.jpg Pegasus Apparent: 6.2 ~33,600 ly Right Ascension: 21h 29m 58.38s; Declination: +12° 10′ 00.6″ Messier Catalogue U of Alabama
M15 is one of the oldest known and closest globular clusters to Earth.
Carina Nebula CarinaCombined.jpg Carinanebula.jpg Carina Apparent: 1.0 ~7500 ly Right Ascension: 10h 45m 04s; Declination: -59° 41' 03" Chandra Universe Today
The Carina Nebula is a very bright and large nebula. It contains Eta Carinae, which is one of the largest known stars and a prime candidate for a hypernova.
T Tauri TTauri.jpg T Tauri 2MASS.jpg Taurus Apparent: 9.3-14 462 ly Right Ascension: 04h 21m 59.43s; Declination: +19° 32′ 06.42″ NASA APOD Universe Today
T Tauri is the prototype for T Tauri stars, which are the stars in the life stage between protostar and main sequence. there is a nebula located close to the star called Hind's Variable Nebula, which changes in luminosity as T Tauri varies.
Sirius B SirB.jpg Canis Major Apparent: 8.30; Absolute: 11.18 8.6 ly Right Ascension: 06h 45m 11s; Declination: -16° 42' 05.00" Chandra NASA APOD
Sirius B is the smaller, white dwarf component to the Sirius star system.
RR Lyrae RRL.jpg RRlyrae.gif Lyra Apparent: 7.1 to 8.2 ~850 ly Right Ascension: 19h 25m 27.91s; Declination: +42° 47′ 03.69″ AAVSO Encyclopedia of Science
RR Lyrae is the prototype for RR Lyrae variables, which are low-mass stars that pulsate regularly.
U Scorpii UScorpii.jpg Usco.png Scorpius Apparent: 8.7 to 19.3 >15000 ly Right Ascension: 16h 22m 30.78s; Declination: -17° 52′ 42.8″ Universe Today Sky and Telescope
U Scorpii is a recurrent nova, and one of ten known recurrent novae in the Milky Way. Its most recent outburst was in January 2010, and it was the best-observed outburst in history.
Rosette Nebula (Caldwell 49, 3C 163) Rosette.jpg Rosette Nebula.jpg Monoceros Apparent: 9.0 4700 ly Right Ascension: 06h 31m 52.00s; Declination: +04° 55' 57.00" Atlas of the Universe Chandra
A large stellar nursery that produces several O and B type stars. It has an appearance similar to a rose, hence its name.
BP Psc BPP.jpg Pisces Apparent: 11.9 ~1000 ly Right Ascension: 22h 22m 24.70s; Declination: -02° 13' 41.40" Chandra NASA NGC 2440 PDF
BP Psc appears to be a red giant, but it has an accretion disc similar to that of a protostar. This has led to hypotheses that BP Psc has recently consumed a companion star or a large, gaseous planet.
NGC 2440 (VV 45) NCG2440.jpg Ngc2440.jpg Puppis Apparent: 11.5 ~4000 ly Right Ascension: 07h 41m 54.91s; Declination: -18° 12′ 29.7″ NASA APOD Hubble
NGC 2440 is a planetary nebula whose star of origin is now an extremely hot white dwarf.
RX J0806.3+1527 (HM Cnc) RXstar.jpg Cancer Apparent: 21.1 ~1600 ly Right Ascension: 08h 06m 23.20s; Declination: +15° 27' 30.20" Chandra
An x-ray binary system composed of two white dwarves that are rapidly orbiting each other. Their orbits are slowly getting closer, and the stars will eventually collide. Since they are faint, they are being observed by x-ray emissions.
DEM L238 & L249 DEMsnrs.jpg Deml238 l249.jpg Dorado ~160,000 ly Right Ascension: 05h 34m 08.80s; Declination: -70º 34' 28.00" Chandra Space Daily
Two remnants from neighboring stars that exploded as white dwarves in the LMC.
2011 DSOs
2011 DSO's
Name Images Constellation Magnitude Distance Coordinates External Links
Epsilon Aurigae Epsilon aurigae.jpg Epsilon Auriga.jpg Auriga Apparent: 2.9 normally, 3.8 during eclipse; Absolute: -6.0 ~2000 light years (ly) Right Ascension: 05h 01m 58.1s; Declination: +43° 49’ 24” AAVSO: Epsilon Aurigae Citizen Sky: Epsilon Aurigae
Epsilon Aurigae is an eclipsing binary. One part is a white giant, and the other appears to be a star shrouded by a dark cloud of dust. In the middle of this cloud, there is a clearing where the star probably is, so during an eclipse, the system appears momentarily brighter as this clearing passes over the giant. An observation project of Epsilon Aurigae took place from 2009-2011.
NGC 6240 (IC 4625, UGC 10592, PGC 59186, VV 617) Ngc 6240.jpg Ngc 6240 xray inset.jpg Ophiuchus Apparent: 12.8 ~330 million ly Right Ascension: 16h 52m 58.9s; Declination: +02° 24' 03" Chandra: NGC 6240 NASA APOD: NGC 6240
NGC 6240 is an extremely luminous infrared galaxy (ULIRG). It is the result of two smaller galaxies colliding to form one large galaxy with two nuclei and an irregular shape. Possible hypotheses for the high infrared emission are intense star formation or the presence of one or two AGNs.
3C 321 3C321 wavelengths.jpg 3c321 artist.jpg Serpens ~1.4 billion ly Right Ascension: 15h 31m 42.7s; Declination:: +24° 04’ 25.00" Chandra: 3C 321 3C 321
3C 321 is a binary system of galaxies. One of the galaxies is directing a large jet of energy at its companion. It is nicknamed the “Death Star Galaxy” and it is theorized that the galaxy with the jet contains a supermassive black hole. It was discovered in 2007.
Centaurus A (NGC 5128, Arp 153, PGC 46957, Caldwell 77, 4U 1322-42) Centaurus Apparent: 6.84 ~15 million ly Right Ascension: 13h 25m 27.6s; Declination: -43° 01’ 09” SEDS: Centaurus A Centaurus A
Cen A is one of the closest radio galaxies containing an AGN to Earth. It is the fifth brightest galaxy in the sky, although it is mostly only observable from the Southern Hemisphere. It is slowly consuming another spiral galaxy, causing rapid star formation, helping the radiation coming from the nucleus. The supermassive black hole at the center sends out jets of X-rays and radio waves in which the inner parts are moving at one half of the speed of light.
Stephan's Quintet (HGC 92, Arp 319, VV 288) Pegasus Apparent: 13.9 300-370 million ly Right Ascension: 22h 35m 57.5s; Declination: +33° 57’ 36” Chandra: Stephan's Quintet NASA APOD: Stephen's Quintet
Stephan's Quintet is a visual grouping of five galaxies. Four of the galaxies are in a compact group, and collisions have altered the form of the galaxies. Eventually, the four will likely merge into one large galaxy. The collisions have caused emissions of both x-rays and molecular hydrogen. The four than are physically interlocked are NGC 7317, NGC 7318a, NGC 7318b, and NGC 7319. NGC 7320 is not actually part of the interacting cluster but is a foreground object in the same area as the other galaxies. The galaxies NGC 7335, NGC 7336, and NGC 7337 in the NGC 7331 group, or Deer Lick Group, was used to determine this. Occasionally, the tidal forces cause NGC 7318b to emit huge shock waves of X-rays. It is also the brightest member of the group with an apparent magnitude of 13.9. NGC 7319 is classified as a Type 2 Seyfert galaxy.
MACSJ0717.5+3745 Auriga Right Ascension: 07h 17m 31.00s; Declination: +37° 45’ 39.60” Chandra: MACSJ0717.5+3745
MACSJ0717.5+3745 (MACSJ0717 for short) a galaxy cluster where four separate galaxies have been involved in a collision. The collisions are caused by a stream of hot gas known as a filament that pours into the cluster. It is one of the most complex clusters ever studied and was discovered in 2003.
Bullet Cluster (1E 0657-56) Carina Right Ascension: 06h 58m 37.9s; Declination: - 55° 57’ 0” Chandra: Bullet Cluster NASA APOD: Bullet Cluster
The Bullet Cluster is a system of two colliding clusters of galaxies. It is one of the best examples of evidence for the existence of dark matter. In the collision, the stars mostly did not interact, but the gases and other matter were significantly altered. This other matter is hypothesized to be dark matter, and is supported by the supposed Modified Newtonian Dynamics that explains the lensing phenomenon in the cluster. It is one of the hottest known clusters of galaxies.
Perseus A (NGC 1275, PGC 12429, UGC 2669, Caldwell 24, 3C 84, QSO B0316+413) Ngc1275 web.jpg Perseus Apparent: 12.6. Right Ascension: 03h 19m 48.1s; Declination: +41° 30’ 42” NASA APOD: Perseus A Hubble Heritage: Perseus A
Perseus A is a Type 1.5 Seyfert galaxy, which signifies that both broad and narrow lines on the emission spectrum are present, but there are less pronounced broad lines than a Type 1 Seyfert galaxy. It consists of two galaxies, one in the center and another that lies in front of it. Long filaments of gas stretch out from the system.
SN 2006gy Perseus Peak Apparent: 14.2 Right Ascension: 03h 17m 27.10s; Declination: +41° 24’ 19.50” Chandra: SN 2006gy NASA APOD: SN 2006gy
SN 2006gy was an extremely energetic supernova that reached an extremely high luminosity level. The large size of the star caused it to gain energy in its core, eventually causing it to be blown apart violently. This type of supernova is sometimes referred to a hypernova, and it compared to the star Eta Carinae in the Milky Way.
SN 1996cr Circinus Right Ascension: 14h 13m 10.05 s; Declination: -65° 20’ 44.8” Chandra: SN 1996cr
SN 1996cr is a powerful supernova that was noticed in a Chandra image after it was taken, and was widely studied afterward. The star exploded between 1995 and 1996, but was not discovered until 2001. It is of interest because it is located in an active galaxy with a growing supermassive black hole and rapid star formation.
NGC 4603 (PGC 42510) Centaurus Apparent: 12.3 Right Ascension: 12h 40m 55.2s; Declination: -40° 58’ 35” NASA APOD: NGC 4603 HyperPhysics: NGC 4603
NGC 4603 is a large spiral galaxy. It is the most distant galaxy in which Cepheids have been used to determine the distance to the galaxy. Using this distance and determining recession velocity, it has served as a benchmark for determining the Hubble constant (70 km/sec/Mpc ±10%).
NGC 7771 (VV 2002) Pegasus Apparent: 12.9 Right Ascension: 23h 51m 25.0s; Declination: +20° 06’ 49” NASA APOD: NGC 7771
a large spiral galaxy in close proximity to two other galaxies. This trio of galaxies is named the NGC 7771 group after its largest member, a spiral, the three galaxies, NGC 7769-7771, have passed by each other closely and will eventually form one huge galaxy. It is considered an accurate representation of the formation of the Milky Way. Dusty nebulae in front of the group obstruct clear viewing.
NGC 2623 (Arp 243) Cancer Apparent: 13.9 Right Ascension: 08h 38m 24.1s; Declination: +25° 45’ 01” NASA APOD: NGC 2623 Hubble: NGC 2623
a system of two or more interacting galaxies. The galaxies have formed one common nucleus, but there are two strands of stars branching out from the galaxy, indicating a merger has taken place.
JKCS041 Chandra: JKCS041
An extremely distant galaxy cluster, about 10.2 billion years away. This object may help scientists better understand how the universe developed at an early age.
Messier 77 (NGC 1068, UGC 2188, PGC 10266, Arp 37, 3C 71) Chandra: Messier 77 Universe Today: Messier 77
One of the nearest and brightest galaxies containing a supermassive black hole. Million-mile per hour wind from the black hole shapes the galaxy.
H2356-309 Chandra: H2356-309
A collection of extremely distant warm hot intergalactic medium, some of the “missing matter” in the nearby universe.
  • Basic note sheet for the 2011 DSOs, intended for use when asked to quickly identify things, or for those new to the event.
2010 DSOs

-**is part of a special viewing campaign this year and will be included up to at least 2011.

See Also

Astronomy/Stellar Evolution
Astronomy/Variable Stars
Astronomy/Star and Planet Formation
Astronomy/Type Ia Supernovae
Astronomy/Type II Supernovae


Basic note sheet for the 2011 DSOs
SIMBAD Astronomy Database for DSOs