Absolute color - magnitude diagram

Click For Summary
SUMMARY

The discussion centers on the need for an absolute color-magnitude diagram (CMD) for Main Sequence fitting to determine distances to star clusters. The user seeks data tables containing absolute magnitudes and colors (B-V and V) for over 100 stars, rather than graphical representations. A suggestion was made to utilize the SIMBAD database, which provides apparent magnitudes and distances for many stars, enabling the calculation of absolute magnitudes. The conversation highlights the importance of distinguishing between apparent and absolute magnitudes in CMD analysis.

PREREQUISITES
  • Understanding of Main Sequence fitting in astrophysics
  • Familiarity with color-magnitude diagrams (CMD)
  • Knowledge of the SIMBAD astronomical database
  • Basic concepts of apparent vs. absolute magnitudes
NEXT STEPS
  • Explore the SIMBAD database for star data, focusing on absolute magnitudes and colors
  • Research methods for calculating absolute magnitudes from apparent magnitudes and distances
  • Learn about the significance of color indices in stellar classification
  • Investigate existing datasets or catalogs that provide absolute CMD data for nearby star clusters
USEFUL FOR

Astronomers, astrophysics students, and researchers involved in stellar distance measurement and color-magnitude analysis will benefit from this discussion.

captain.joco
Messages
32
Reaction score
0
Hello all,

I am finding a distance to a cluster via Main Sequence fitting, and I don't know where to find an absolute color - magnitude diagram ( B-V, and V ). I can be from any star cluster, or sky region, as long as the magnitudes are absolute. I need the data tables, not just a pretty picture ( that Google with easily show ). If you have idea where to find some data, please do tell me ( I ideally, I would like to plot more then 100 stars on my color magnitude diagram ).

Thank You all!
J.
 
Astronomy news on Phys.org
simbad has apparent magnitudes for a lot of stars in both the B and V bands. It also has the distances to many of these stars so you can find their absolute magnitudes.

From my experience, when dealing with filters capital letters need not mean absolute magnitude. Usually B-V is done in apparent magnitude. It shouldn't matter except for preferential extinction which will be negligible for closer stars.
 
Hey thanks for your answer. I have thought of that, but I wouldn't like to do that manually for ~100 stars.. Isnt any ready data table of absolute magnitudes and colors out there ( at least for near by stars? ) Thanks
 

Similar threads

Undergrad Help with the color of a star cluster
  • · Replies 1 ·
Replies
1
Views
2K
Undergrad How to Determine Absolute Magnitude
  • · Replies 1 ·
Replies
1
Views
3K
Undergrad Absolute Magnitude Calculation, How?
  • · Replies 2 ·
Replies
2
Views
5K
Graduate How Can I Filter Known Globular Clusters in SDSS Data?
  • · Replies 1 ·
Replies
1
Views
1K
Undergrad How to calculate absolute magnitude of a stellar body?
  • · Replies 6 ·
Replies
6
Views
4K
Graduate How do I define Open cluster membership?
  • · Replies 5 ·
Replies
5
Views
3K
Graduate Apparent Birghtness And Absolute Brightness
  • · Replies 1 ·
Replies
1
Views
2K
High School More Evidence for MOND -- Globular cluster galactic acceleration imprint
  • · Replies 1 ·
Replies
1
Views
2K
Undergrad Where can I find publicly accessible data from observatories in Europe?
  • · Replies 5 ·
Replies
5
Views
2K
Star maps using Blender
  • · Replies 19 ·
Replies
19
Views
1K