So if I'm given that a star travels 3.45 mas in 44 years at a distance of 167 pcs and I'm trying to get the tangential velocity (this is a problem from the 2017 Golden Gate invitational that I've been stuck on), I would do 3.45/1000/3600 to convert it to degrees, divide that by 44 for the proper motion in degrees/year, and multiply it by 167 to get the tangential velocity? When I do that and convert to km/sec, I get an answer about 100 times less than the given answer of 364 km/sec. Can anyone tell me what I'm doing wrong?Proper motion in terms of angle is just the angle divided by the time, exactly as you said. To find proper motion in units of distance per time, you'll need to know the distance and use the small angle approximation to determine the length of the angular proper motion (or if it's close enough, the approximation may not be very good and you'll have to use tangent of the angle).
I think you should be converting to radians to get an accurate ratio. Note that the key for that test is incorrect on math in several places.So if I'm given that a star travels 3.45 mas in 44 years at a distance of 167 pcs and I'm trying to get the tangential velocity (this is a problem from the 2017 Golden Gate invitational that I've been stuck on), I would do 3.45/1000/3600 to convert it to degrees, divide that by 44 for the proper motion in degrees/year, and multiply it by 167 to get the tangential velocity? When I do that and convert to km/sec, I get an answer about 100 times less than the given answer of 364 km/sec. Can anyone tell me what I'm doing wrong?Proper motion in terms of angle is just the angle divided by the time, exactly as you said. To find proper motion in units of distance per time, you'll need to know the distance and use the small angle approximation to determine the length of the angular proper motion (or if it's close enough, the approximation may not be very good and you'll have to use tangent of the angle).
The data table from Wikipedia (augmented with info from other sources if needed for that particular DSO), lots of different images with descriptions (including the part of the EM spectrum and the telescope/satellite/etc. that took the image), light curves and spectra (also with descriptions), and text with important info (e.g. how it was formed, what type of object it is, what it may do in the future, pretty much anything). It typically takes me around 1 hour per DSO (I did all of them right after the rules came out), though if you're new to the event it'll probably take a little longer.Hello, this is my first time doing Astronomy this year, and im rather overwhelmed by all the topics
What are the important things to have in a binder for DSO's?
https://scioly.org/wiki/images/c/c6/Formula_Sheet.pdfHi. I'm new to Astro. I need help. How do you calculate absolute magnitude of a star given its radius and temperature?
Also any tips for the formulas I need to know? Thanks
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