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Re: Astronomy C

Posted: June 13th, 2012, 2:49 am
by AlphaTauri
DSO predictions:
r136a1
Eta Carinae
VY Canis Majoris
Betelguese
A few type II SNR's

Any other ideas?
I've been writing an astro test based on high-mass stars/Type II SN and currently, my potential DSO list is this:

Crab Pulsar
SN 1987A
Cas A
Eta Carinae
r136a1
VY Canis Majoris
M33 X-7
Cygnus X-1
Cygnus X (?)
Vela Pulsar (?)
M45 Pleiades (?)
Rosette Nebula (?)
M16 Eagle Nebula (?)
S Monocerotis (?)
V838 Monocerotis (?)
Pistol Star (?)
PSR J1748-2446ad (?)
RX J1856.5-3745 (?)
Yeah that's a hypergiant in the LMC with around 286 solar masses now, and a birth mass believed to be about 360 solar masses right? Also, scientists are not sure how it got that big; above 150 solar masses, protostars should just blow themselves apart (like obese people :P).
Well, the Eddington Limit is somewhat famous for being broken time and time again...

This guy seems to be doing some research with super-Eddington objects, and he argues that inhomogeneous stellar atmospheres allow the outward radiation to escape through less-dense areas, pushing less of the star's mass outwards and thus allowing objects to exist with masses above the Eddington Limit. It's worth noting as well that even the modified Eddington Limit doesn't take all potential factors into account, so maybe we shouldn't really be that surprised when the reality doesn't match up with the theory.

Re: Astronomy C

Posted: June 13th, 2012, 8:17 am
by Cheesy Pie
Crab Pulsar - pulsar in Crab Nebula
SN 1987A
Cas A - supernova remnant, about 11000 ly away from earth, supernova obscured, but reached Earth in 1500s
Eta Carinae binary supergiants nearing ends of lives, at least one believed to go supernova sometime soon, emitted gas in shape of two lobes
r136a1 hypergiant in Large Magellanic cloud, large (280 something sol masses now, >300 sol masses at birth)
VY Canis Majoris red hypergiant with diameter greater than any other star
M33 X-7
Cygnus X-1 famous black hole candidate, believed to be black hole because of supergiant companion's motion
Cygnus X (?)
Vela Pulsar (?)
M45 Pleiades (?) open cluster easily visible from Earth, 440 ly across, includes many stars, brightest is Alcyone (Eta Tauri)
Rosette Nebula (?)
M16 Eagle Nebula (?) starforming region about 7000 ly from earth, famous features include "pillars of creation" and Spire
S Monocerotis (?)
V838 Monocerotis (?) red supergiant in outer reaches of galaxy, recently had massive brightness fluctuations
Pistol Star (?) Hypergiant in Quintuplet Cluster, near center of Milky Way, >100 sol masses, millions of times brighter than sun, would be visible in night sky w/o telescope if not for interstellar dust
PSR J1748-2446ad (?)
RX J1856.5-3745 (?)


Oh and thanks Alpha.

Re: Astronomy C

Posted: June 13th, 2012, 8:38 am
by Schrodingerscat
When I think about it, we might get r136 in general as it would actually give us an image to identify, and contains several stars that break the mass limit.

Re: Astronomy C

Posted: June 13th, 2012, 11:22 am
by Cheesy Pie
It's an open cluster in the Tarantula Nebula (30 Doradus), isn't it?

Re: Astronomy C

Posted: June 13th, 2012, 5:26 pm
by AlphaTauri
When I think about it, we might get r136 in general as it would actually give us an image to identify, and contains several stars that break the mass limit.
True, true. The same might apply for the Crab Pulsar/M1 Crab Nebula if it ends up on the official list.

I'm slightly concerned about how we're supposed to ID pulsars and other radio sources since they're not too distinctive visually - perhaps graphs or sommat (akin to RR Lyrae, U Scorpii, RX J0806 for the past year)?

Edit: On the topic of potentially returning DSOs, I actually think the Rosette Nebula has a good chance of returning due to all the O/B stars being formed in the region. Mira might as well, since it's a high-mass varstar, and I suppose the Carina Nebula is a possibility, although they'd likely narrow it to Eta Carinae.

Re: Astronomy C

Posted: June 14th, 2012, 7:22 am
by Cheesy Pie
Crab Nebula: supernova remnant of Type II, famous for light reaching earth in 1054 AD and being visible in daylight for 23 days, 6500 ly away from Earth, famous pulsar

Re: Astronomy C

Posted: June 14th, 2012, 12:05 pm
by pjgscioisamazing
Mira might as well, since it's a high-mass varstar
Mira is a solar mass variable star (well just over 1 Solar Mass), it's on the AGB which is eventually what the sun will become. Mira will shed it's outer layers and become a white dwarf at the end of its red giant phase.

Also I don't think Carina Nebula will be on the list. I can see them simply putting on Eta Carinae

Re: Astronomy C

Posted: June 14th, 2012, 12:23 pm
by Cheesy Pie
Mira might as well, since it's a high-mass varstar
Mira is a solar mass variable star (well just over 1 Solar Mass), it's on the AGB which is eventually what the sun will become. Mira will shed it's outer layers and become a white dwarf at the end of its red giant phase.
You're talking about Mira A, right? Mira B is a white dwarf star that's pulling mass off of its companion.

Re: Astronomy C

Posted: June 14th, 2012, 1:15 pm
by pjgscioisamazing
Mira might as well, since it's a high-mass varstar
Mira is a solar mass variable star (well just over 1 Solar Mass), it's on the AGB which is eventually what the sun will become. Mira will shed it's outer layers and become a white dwarf at the end of its red giant phase.
You're talking about Mira A, right? Mira B is a white dwarf star that's pulling mass off of its companion.
Yes that was all in reference to the primary in the system

Re: Astronomy C

Posted: June 14th, 2012, 1:20 pm
by Cheesy Pie
Thanks. Also, infrared images of Mira A reveal a stream of atmosphere created by its companion's gravity, which I find very interesting.