Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [cepheids]

Use when your question is specifically about Cepheid variables.

4
votes
2answers
67 views

Classification and discovery of stars

How do astronomers find the difference between a 'Cephid Variable Star' and distinct normal stars with opaque objects blocking it's light, like stars with planets revolving around them while both ...
2
votes
0answers
49 views

Type I delta-Cepheid star, calculation of apparent maginute and luminosity

I am curious to see if I have calculated this correctly: A Type I delta-Cepheid star with a one month (30day) period is put at the distance of the star Vega. a) Determine the apparent magnitude ...
1
vote
1answer
560 views

How to find a Cepheid's pulsation period using its graph?

Basically, I've been seeing these graphs that say: Cepheid Period-Luminosity Relation and the Period axis is supposed to be "logarithmic"; How does this graph work? Since the luminosity of a star ...
1
vote
0answers
40 views

Interstellar reddening for Cepheids

How were interstellar reddening values for cepheid first calculated? I mean, other than using the derived equation to get extinction-corrected magnitude of Cepheids, I want to know how to drive them ...
1
vote
0answers
54 views

Calculating angular diameter amplitude from angular diameter variations of Cepheid variable

I'm a high school student but have as much interests in Cepheid variable as the professionalists. I'm trying to derive independent distances to Cepheid with the Baade-Wesselink method. I got the ...
5
votes
2answers
531 views

Did Gaia actually generate complete light curves for 212 Cepheids in other galaxies?

The recent BBC news item Gaia clocks speedy cosmic expansion says that a recent Gaia measurement of 212 Cepheid variables in other galaxies within the local group yields a Hubble constant of ~73 km/s/...
2
votes
0answers
44 views

Using the surface-brightness relation for Cepheids

I'm a high school student who is doing research about Cepheid variables. I'm in the process of deriving distance to Cepheid using the Baade-Wesselink method, which utilises the surface brightness ...
0
votes
1answer
52 views

How to calculate a phase shift in the process of deriving Baade-Wesselinke distance?

The above is the equation used in the Baade-Wesselink method to independently get distances to Cepheid variables (in the process of deriving Period-Luminosity relation). According to the paper New ...
0
votes
1answer
119 views

Which software is appropriate to integrate radial velocity with respect to time [closed]

I'm a high school student and currently I'm trying to use Baade-Wesselink method to independently derive period-luminosity relation of Cepheid variables. I noticed that to get the linear radius ...
2
votes
2answers
96 views

Deriving phase of a pulsating star from list of Julian date values of observing brightness

I want to convert the list of Julian date values of observing brightness of a Cepheid variable into its phase. The equation I found in the Internet is the following: $$\mathrm{Phase}= \frac{\mathrm{...
1
vote
0answers
44 views

Change in angular diameter of Cepheid variables

I'm a highschool student and in the process of writing a research paper of deriving period-lumniosity relation of Cepheid variable independently of the pre-existing PL relation. Thus, I need to derive ...
1
vote
0answers
90 views

Integrating radial velocity with respect to time

I'm a highschool student who is writing a research paper about plotting Period-Luminosity graph of the Cepheid variables by deriving distance through independent method such as trigonometric parallax ...
2
votes
1answer
212 views

How does the cepheid variables help in finding distance

How did Edwin Hubble find distances using Cepheid variables as 'standard candles'?
2
votes
2answers
150 views

Stars in star clusters in SMC and LMC

Is there any catalog or any paper published in any journal that lists the stars discovered under whichever star cluster of the Small Magellanic Cloud (SMC) they belong to? There is one for Large ...
2
votes
1answer
139 views

Distance of extra-galactic Classical Cepheids

There have been many questions and answers about finding the distance of a star from the earth. But as I did some research on the net, I found that we have specific approaches for finding the ...
4
votes
3answers
322 views

Pulsation Modes of Cepheids

There are various modes of Cepheids like single modes: fundamental (F), first overtone (1O), and likewise. And then we have double modes: F/1O, 1O/2O etc. triple modes: 1O/2O/3O etc. What ...
7
votes
1answer
307 views

How do we know that the intrinsic brightness of Cepheid variables corresponds to their period?

As I understand it, beyond parallax the next way of estimating the distance to astronomical objects is by using a relationship between the period and intrinsic luminosity of Cepheid variables. How do ...