10 votes
Accepted

Confused about rubber sheet analogy!

The rubber sheet only is not meant to be a qualitative model, it gives one concept and one concept only: Mass causes curvature of spacetime. You can't get any more than that from the rubber sheet. ...
user avatar
  • 87.6k
6 votes

What caused instant jumps and exactly flat periods in Kepler's light curves?

There are two separate points of interest you're looking at so I'll separate this into sections. Sudden Drop at Day 1559 As near as I can tell, this is the result of a quarterly roll of the ...
user avatar
  • 14.4k
5 votes

Confused about rubber sheet analogy!

I just wrote an answer about this. The rubber sheet is a good model of 2D Newtonian gravity, with a 1/r force law. If you make a rigid surface in the shape of the 3D gravitational potential, like the ...
user avatar
  • 2,065
5 votes

Get orbital period of exoplanet from light curve using astropy.timeseries

The second light curve you show has no obvious periodic behaviour and I cannot see any sign of a planetary transit. The period-finding algorithm appears to be working correctly. The planet (if it ...
user avatar
  • 114k
4 votes
Accepted

Classification and discovery of stars

Cepheid variable stars and exoplanets transiting stars have very different light curves (the relation between brightness and time). Exoplanet light curve from NASA: Cepheid variable light curve from ...
user avatar
  • 1,234
4 votes

Could Tabby's star be beamed by a neutron star's jet causing irregular star spots?

I think this scenario is unlikely. There is no evidence Tabby's star is near a neutron star. Astronomers are monitoring Tabby's star very closely and there has not been any detection of the radio ...
user avatar
  • 421
4 votes

Converting Light curve to Luminosity

To calculate a "luminosity light curve" from a time series of V-band photoetry, you need two things. You need to know the distance. The distance to Betelgeuse is uncertain and that means ...
user avatar
  • 114k
4 votes
Accepted

How do you tell if a variable star is periodic or not by its light curve?

There are some nice and well-tested routines to create periodograms and test the periodicities for significance in the astropy.timeseries package, containing the LombScargle class. This class includes ...
user avatar
  • 114k
4 votes
Accepted

How much time do I have left to easily spot the recently brightened Recurrent Nova RS Ophiuchi with binoculars and mild light pollution?

RS Ophiuchi is "Currently" Shining at a apparent magnitude of 5.12 (initially 4.6.) . It is fading at a rate of 0.01 and continues this progress for the next 43-47 days. Then it will fade at ...
user avatar
3 votes

Binning a Phase Folded Lightcurve

tl;dr: try a finer frequency grid to obtain the correct period, bin it with the function astropy.timeseries.aggregate_downsample Before addressing the binning, you ...
user avatar
  • 2,676
3 votes

Calibrating raw photometric measurements

I have never worked with SMEI but I do have some experience with photometry and, while I do not understand completely the question, I think I can give you some ideas. First of all, did you get the ...
user avatar
3 votes
Accepted

Calibrating raw photometric measurements

If I understand the question correctly, you have raw data from a CCD sensor in arbitray units (which correlate with brightness) and your challenge is to callibrate this intensity for a certain ...
user avatar
  • 5,284
3 votes
Accepted

Get orbital period of exoplanet from light curve using astropy.timeseries

I think you may be seeing the planet in the periodogram! But also another signal - higher harmonics of other periodic signals example - various periodic signals in our sun - with a characteristic ...
user avatar
  • 148
3 votes

Where can I download processed data of the Kepler telescope?

What you are looking for is here. http://archive.stsci.edu/kepler/search_retrieve.html This one is good for exoplanet light-curves https://exo.mast.stsci.edu/
user avatar
3 votes
Accepted

Plot SuperWasp Lightcurves

Not sure what you are expecting to see from the two datasets. Both datasets are examples of light curves, flux against time with different arbitrary origins for the time axis; SuperWASP ...
user avatar
  • 7,135
2 votes

Comprehensible full manual for bolometric light curve reconstruction

If you want a bolometric light curve from photometric points, you don't need to reconstruct its SED inside the range you already have data points. Use effective central wavelength of each band with ...
user avatar
2 votes
Accepted

Calculate depth and duration of exoplanet's transit using Python, astropy or lightkurve

Calculation of both, depth and duration, is usually done not on the raw data but derived from a fit to the data. In your last three lines of code you also calculate the average / medium over all data ...
user avatar
  • 10.7k
2 votes
Accepted

Obtaining the Light curve of a a Quasar

As described in Paris et al. 2018, in that catalog you don't have the info for creating light curves. If you go like here: http://skyserver.sdss.org/dr16/en/tools/chart/navi.aspx you can get the ...
user avatar
2 votes

How to find luminosity from a light curve?

It's unclear what kind of luminosity you're trying to determine. If it's bolometric luminosity (from photons of all wavelengths), then planetmaker is right, and you need (calibrated) observations at ...
user avatar
  • 14.7k
2 votes
Accepted

Sudden spikes on the light curve of a Quasar from K2 mission

While I am not really familiar with Kepler, there is the following paper by Vanderburg & Johnson, where they explain: Extracting raw photometry and centroid positions from the K2 images results ...
user avatar
  • 2,400
1 vote

Obtaining the Flux-Time plot for a Quasar

So I found the MAST archival repository to be very helpful to obtain the processed FITS file for the object of my interest. We can enter the object's name (if it's a popular object) or the galactic ...
user avatar
  • 165
1 vote

Calculate mass of exoplanet from transit method

Antispinwards is correct. However, for the practical purpose of estimating a mass, you can construct a mass-radius plot for all the exoplanets with known mass, use this to define a mean mass-radius ...
user avatar
  • 114k
1 vote
Accepted

How to recognize exoplanet transit

Of course you will get multiple peaks in the periodogram. The Fourier series representing a non-sinusoidal signal will contain frequencies at multiples of the fundamental frequency. Similarly, you can ...
user avatar
  • 114k
1 vote
Accepted

How can I estimate the initial luminosity of a SNIa given initial mass of Ni-56?

Nickel 56 decays to Cobalt 56 via electron capture decay, with a half-life of 6.1 days and a decay constant of $\lambda = 1.31\times 10^{-6}$ s$^{-1}$. About 1.75 MeV of energy is lost as gamma rays ...
user avatar
  • 114k
1 vote

How Can I interpret this particular light curve without reading data on the side

The radius of the planet is 0.17% of Jupiter's radius. Under the "Planet" info on the left, it says $R_P$ which is the radius of planet, and since the units are shown as $[R_J]$ this is the ...
user avatar
1 vote
Accepted

Pair together light curve and radial velocity data of specified star

An excellent page to get most or all names for a star is Simbad which also happens to know the Kepler IDs (KID). Ont the other hand, every of the RV data files contains info on the star's identifier ...
user avatar
  • 10.7k
1 vote
Accepted

What are these data in light curve generator

The file format for submitting observations to AAVSO sheds some light on this. "Visual" data are estimates by visual comparison to nearby reference stars of similar brightness. U, B, V, R, I data ...
user avatar
  • 16.5k
1 vote
Accepted

Python: Find brightest pixel in fits-file and ignore brighter artefacts

Following Mick's comment, I found an astropy-function - DAOStarFinder - that does what I was looking for. It scans an image for light-sources and one can set threshhold for a detection, e.g. the "...
user avatar
  • 293

Only top scored, non community-wiki answers of a minimum length are eligible