B What is the best source for this star data? (M44 Beehive Cluster)

[terado]

TL;DR Summary

what's the easiest way to get this star data?

Hi

I need the below data for the thousand or so stars in M44 the Beehive Cluster. What would be the easiest way to get this data?

Thank you.

RA, Dec, distance, apparent magnitude, absolute magnitude, spectrum

 

[Bandersnatch]

Have you tried/are you familiar with astronomical databases? Simbad, Aladin, VizieR, Gaia Archive?
You can query them for raw astrometric and photometric data, but derived parameters are harder to come by. So you should be able to get RA, dec, apparent magnitudes in different bands - parallax (i.e. distance) probably best if you go to Gaia - for most objects in the designated area. But absolute magnitude and spectral type are unlikely to be listed. You can calculate the former from distance and apparent magnitude, though.

If you've never used these before, there's something of a learning curve to surmount. Look in their help sections, maybe search for some tutorials on youtube.

 

[phyzguy]

I would start with Stellarium, which is a free download (https://stellarium.org/). You just click on the stars you are interested in, and you will get everything you listed except the spectrum, although you will get the spectral type. I'm attaching a screenshot.

 

[Bandersnatch]

I would star with Stellarium

A bit tedious if one wants to do it for ~1k objects.

 

[Vanadium 50]

Even Wikipedia has all of that information, except spectrum. To be honest, I don't know what "the" spectrum from 1000 sources even means. You might find B-V, or the spectrum of some characteristic stars, but I think you will need to ponder what it is you want.

 

[Hyperfine]

You might try the Sloan Digital Sky Survey

They provide a number of increasingly recent data sets which include spectra of over 4 million astronomical objects.

 

[terado]

Have you tried/are you familiar with astronomical databases? Simbad, Aladin, VizieR, Gaia Archive?
You can query them for raw astrometric and photometric data, but derived parameters are harder to come by. So you should be able to get RA, dec, apparent magnitudes in different bands - parallax (i.e. distance) probably best if you go to Gaia - for most objects in the designated area. But absolute magnitude and spectral type are unlikely to be listed. You can calculate the former from distance and apparent magnitude, though.

If you've never used these before, there's something of a learning curve to surmount. Look in their help sections, maybe search for some tutorials on youtube.

Thanks.
That learning curve is exactly the reason I'm asking here!!
I did find those databases (except for the Gaia Archive) but couldn't work out how to submit a simple query like "M44 and all its 'children' stars" or "all stars within x parsecs of the centre of M44". I also had trouble finding decent tutorials.

There are about 25 bright stars in the cluster. I've found detailed information on those. All I really need for the rest is RA, Dec and distance.

 

[phyzguy]

You might try the Sloan Digital Sky Survey

They provide a number of increasingly recent data sets which include spectra of over 4 million astronomical objects.

I tried that, but many of the stars are too bright to be included.

 

[phyzguy]

I just query Simbad using Python. The code snippet below should give you what you want. It returned 2162 items. It's going to be up to you to determine which ones are actually physical members of the Beehive cluster and which ones are chance associations.

import numpy as np
from astroquery.simbad import Simbad
import astropy.units as u
result_table = Simbad.query_region("m44", radius=0.8 * u.deg)
print(result_table)

 

[terado]

I just query Simbad using Python. The code snippet below should give you what you want. It returned 2162 items. It's going to be up to you to determine which ones are actually physical members of the Beehive cluster and which ones are chance associations.

import numpy as np
from astroquery.simbad import Simbad
import astropy.units as u
result_table = Simbad.query_region("m44", radius=0.8 * u.deg)
print(result_table)

Thank you!
I have never used Python or Astroquery before. Just to check .. there is no online method and I have to install Astroquery to be ably to query in this way?

 

[phyzguy]

If you haven't used Python, it's probably best to query Simbad directly from the web interface. Below is a screen shot of the query. It's the same basic syntax and returned the same list of 2162 objects.

 

[terado]

If you haven't used Python, it's probably best to query Simbad directly from the web interface. Below is a screen shot of the query. It's the same basic syntax and returned the same list of 2162 objects.

Thank you!
That got me the data.