# Questions tagged [cepheids]

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### Observing cepheid variables in other galaxies

If individual stars cannot be seen in other galaxies (excluding satellite galaxies of the Milky Way) then how can light from cepheids other galaxies be observed?
91 views

### Lorentz transformation for stars

If a star that has regular pulses(standard candle) is flying away from us at relativistic velocity(very distant), would that pulses look like very sluggish compared to a non-relativistic velocity(...
123 views

### How does the Hubble Space Telescope “Drift and Shift”?

The Phys.org article Mystery of the universe's expansion rate widens with new Hubble data says: Astronomers have been using Cepheid variables as cosmic yardsticks to gauge nearby intergalactic ...
92 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 ...
146 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 ...
894 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 ...
71 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 ...
66 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 ...
622 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/...
59 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 ...
70 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 ...
134 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 ...
205 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{...
53 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 ...
123 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 ...
344 views

### How does the cepheid variables help in finding distance

How did Edwin Hubble find distances using Cepheid variables as 'standard candles'?
212 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 ...
159 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 ...