[ 3 / biz / cgl / ck / diy / fa / ic / jp / lit / sci / vr / vt ] [ index / top / reports ] [ become a patron ] [ status ]
2023-11: Warosu is now out of extended maintenance.

/sci/ - Science & Math

View post   
File: 37 KB, 926x921, M37.png [View same] [iqdb] [saucenao] [google]
5828422 No.5828422 [Reply] [Original]

Hey /sci/,

As part of an astronomy assignment I have to analyse and process images from the cluster M37. I've performed several operations on the images, yielding me useful information considering the flux of 25 different stars in different filters in this cluster.
Using those fluxes I've constructed a colour-magnitude-diagram, with error-margins, but I've got some questions concerning that:

- Am I right to conclude that the left area is the main sequence? If so; would the two lines at Magnitude = ~11 and ~13.5 be part of horizontal branches; (sub)giants?
- Secondly, I would like some help with this question: What distance would you estimate for M37, knowing that the star Vega has been set to have a magnitude of 0 in every filter, and that it has a distance of 7.7 parsec?

Any pointers would be appreciated.

>> No.5828448 [DELETED] 

faget
hue hue

>> No.5828477
File: 1.33 MB, 800x712, Voerman.png [View same] [iqdb] [saucenao] [google]
5828477

>> No.5828514
File: 228 KB, 3000x2025, PIA10398.jpg [View same] [iqdb] [saucenao] [google]
5828514

>> No.5828545
File: 669 KB, 1820x2460, PIA11770.jpg [View same] [iqdb] [saucenao] [google]
5828545

>> No.5828590
File: 495 KB, 2400x3000, 2004-18.jpg [View same] [iqdb] [saucenao] [google]
5828590

>>5828422
Still haven't solved those yet.

Another question:
What's the colour of the heaviest stars that are still on the main sequence? Using this, give an estimate for the age of M37.

--

The heaviest stars on the main sequence obviously are to the most top-left, so they've got a index value of B-V = ~0. I know I've probably got to use isochrones, but I can't find anything to compare it with.

Bump.

>> No.5828654
File: 330 KB, 1024x1024, Mercury.jpg [View same] [iqdb] [saucenao] [google]
5828654

>> No.5828686
File: 52 KB, 750x589, plutoids.jpg [View same] [iqdb] [saucenao] [google]
5828686

>> No.5828714
File: 122 KB, 1239x581, tunefork.jpg [View same] [iqdb] [saucenao] [google]
5828714

>> No.5828756
File: 932 KB, 356x334, Lunar_libration_with_phase2.gif [View same] [iqdb] [saucenao] [google]
5828756

>> No.5828762

>>5828422
0x3928192C
0x4C18293B
0x5392184A

>> No.5828785
File: 154 KB, 800x485, Lunar_perigee_apogee.png [View same] [iqdb] [saucenao] [google]
5828785

>> No.5828820
File: 177 KB, 1536x1229, NVA2~8~8~14580~115121.jpg [View same] [iqdb] [saucenao] [google]
5828820

>> No.5828844

It's been six hours now. Nobody that wants to help? Any idea would be nice.

>> No.5828864
File: 68 KB, 500x667, sunset.jpg [View same] [iqdb] [saucenao] [google]
5828864

>>5828844

>> No.5828940
File: 520 KB, 1024x768, Mercury_mag.jpg [View same] [iqdb] [saucenao] [google]
5828940

>> No.5828989
File: 250 KB, 1512x1512, uranus3.jpg [View same] [iqdb] [saucenao] [google]
5828989

>> No.5828996

>>5828844
This board is for high school homework and reciting things from Wikipedia to try and sound smart. Nobody understands what you're talking about.

>> No.5829009

>>5828996
This. Do you have any calculus homework, OP? I would love to paste the rules and tell you to get out. That would make me look like a badass in front off my /sci/ high school bros.

>> No.5829020

>>5828996
>>5829009
Well, I hoped someone would eventually tag along and share some thoughts about it. There should at least be some credential /sci/entists here.

>> No.5829037

Sorry, I *should* be able to help... I did an astronomy course and had an assignment similar to this but it confused me too much and it stands as the only assignment in my life that i didn't submit. heh.
All i can say is that you probably have to use the distance modulus for your second question,
m - M = 5*log(d), where d is in pc
but that's probably obvious, i dont know

>> No.5829064

Unrelated but I'd like to take an astronomy class myself. How are you liking your class OP?

>> No.5829174

>>5829037
Thought about that too, but couldn't figure anything out. Thanks for the input, will take another look at it later.

>>5829064
I'm actually doing a bachelors degree. First year student, so it's mostly the same stuff as the physics students get. The main difference is that astronomy students get two different courses; one that gives a general introduction into astronomy, and one that teaches you how to use Python and gives a bit of insight in the experimental part of astronomy.
But because I live in the Netherlands, the weather is mostly too awful to do any useful observations, sadly.

>> No.5829193

The main sequence will include the lower section and possibly the left section, but not just the left section, the main sequence is not vertical. My guess is that it is the lower and left sections. It's not clear when the quality of observations is this low.

Calculating the distance to the cluster is much more straight forward. Vega is a main sequence star with B-V=0. On on your plot estimate the magnitude of a B-V=0 star, then use pogson's equation m - M = 5*log(d)) to calculate the distance to the cluster. You should probably calculate the absolute magnitude of Vega first from the information provided rather than looking it up, but it isn't hard.

>> No.5829219

>>5829174
Natuur- en Sterrenkunde aan de UvA?

>> No.5829225

>>5829193
Sadly the quality of the observations is indeed really low. After about four months of waiting people got fed up and it was decided to do some measurements in crappy weather circumstances.

Estimating the magnitude corresponding with B-V=0 yields a fairly wide margin, basically it could be anything between 10.8 and 11.7, which translates to a distance of ~1100-1700 parsec. Compared to the current consensus of 1383 parsec it seems to fit rather nicely.

Concerning the other question: Is there any other method I can use to estimate the age of the cluster, except for comparing it with other colour-magnitude-diagrams?

>>5829219
Sterrenkunde te Leiden.

Thanks for the help guys, was worth the wait.

>> No.5829267

>>5829225

About estimating the B-V=0 magnitude. I would fit a linear relation to the data, ignoring the giant branch. That should give you a decent estimate. You could use other relations if appropriate.
>Is there any other method I can use to estimate the age of the cluster, except for comparing it with other colour-magnitude-diagrams?
If you measure the location on the root of the giant branch also called the turn off (possibly by fitting lines to the giant branch and main sequence to see the intercept) you can measure the most massive star that has just turned off the main sequence. This can be used to estimate the age of the cluster.
A calculation like this would likely suffice:
>http://www.phy.duke.edu/~kolena/hou/clusterage.html

We did a similar lab back in first or second year undergrad but we didn't take data, actually that isn't true we had a virtual telescope program from the 90's. I think it's a bit rough that they haven't given you much instruction on this.

>> No.5829292

>>5829267
Thanks again for the help. We basically got thrown in at the deep end here. No mention of the turn off, no suggestions about how data could be interpreted, nothing.

Hopefully I've got enough measurements to make a decent linear fit of the different parts. Should be able to do everything now.

Again, thanks for chipping in.

>> No.5829378

>>5829174
My school doesn't offer a degree, all we have are 2 astronomy classes and 2 astrophysics classes. The 2 astronomy classes are all introductions that don't require any physics at all and include observation labs. I'll be eligible for the first astrophysics class after this summer, looks interesting but I kind of want to do some actual observation.

>> No.5829381

>>5829378
Actually looking at the catalog better, there are more than just 2 astrophysics classes but I couldn't do one other than the one I mentioned because of physics requirements.