What Is Integrated Visual Magnitude in Astronomy?

  • Thread starter Thread starter tony873004
  • Start date Start date
  • Tags Tags
    Magnitude Visual
AI Thread Summary
Integrated visual magnitude in astronomy refers to the overall brightness of a star cluster, taking into account the magnitudes of individual stars. In the discussed globular cluster with 10,000 stars, 100 stars have a magnitude of 0.0, while the remaining 9,900 have a magnitude of +5.0. A weighted average calculation yields an integrated visual magnitude of approximately 5.0 for the cluster. The term is not defined in class materials or textbooks, leading to confusion among students. Further resources or formulas may be needed for a clearer understanding of this concept.
tony873004
Science Advisor
Gold Member
Messages
1,753
Reaction score
143
A certain globular cluster has a total of 10^4 stars; 100 of them have MV=0.0, and the rest have MV=+5.0. What is the integrated visual magnitude of the cluster?


Nowhere in our class notes or textbook is the term "integrated visual magnitude" defined. Googling it, I find the term used, but not defined.


If I had to guess how to do this problem, I'd just do a weighted average:

M_{cluster}=\frac{(100*0.0)+(9900*5.0)}{10000}

M_{cluster}=4.95

Which when rounded for significant figures = 5.0
 
Physics news on Phys.org
See if these notes and examples help -

http://ottawa.rasc.ca/observers/an9811p9.html

I am a bit surprised that this is not covered in your textbook.
 
Last edited by a moderator:
I was also given this question and I tried clicking the link and it doesn't work. How would I go about starting this? We too didn't learn anything about integrated visual magnitude so I have no idea what to do with this. Is there some type of formula or something?
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'Calculation of Tensile Forces in Piston-Type Water-Lifting Devices at Elevated Locations'

Thread 'Calculation of Tensile Forces in Piston-Type Water-Lifting Devices at Elevated Locations'

Figure 1 Overall Structure Diagram Figure 2: Top view of the piston when it is cylindrical A circular opening is created at a height of 5 meters above the water surface. Inside this opening is a sleeve-type piston with a cross-sectional area of 1 square meter. The piston is pulled to the right at a constant speed. The pulling force is（Figure 2）： F = ρshg = 1000 × 1 × 5 × 10 = 50,000 N. Figure 3: Modifying the structure to incorporate a fixed internal piston When I modify the piston...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

Can you please check my answers to those short astronomy questions?
Replies
1
Views
3K
I How Big of an Object Orbiting Closer to the Sun Than Earth Could Be Overlooked?
Replies
17
Views
3K
Big Bang Big Schmang, astronomical redshift is an artifact of distance
Replies
1
Views
3K
Programs How good is this applied math program?
Replies
13
Views
3K
Challenge Math Challenge - December 2018
2
Replies
67
Views
14K

Hot Threads

Recent Insights

Back
Top