Questions tagged [light-curve]
Questions about the time-dependence of the light intensity of a celestial object or region.
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Why does Mars have a jagged light curve?
Caption:
The following chart is the predicted light curve (visual magnitude as a function of time) of Mars, according to the most recent ephemeris data. Magnitude data is sampled with a 2 days ...
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Gravitational mirroring: Can we theoretically see the Milky Way using a telescope?
As I am watching the beautiful deep field picture of the James Webb Space Telescope. I noticed the gravitational lensing. So I asked myself whether it is possible somehow a successive cluster of ...
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Why did it take so long for SN1987A to reach peak brightness?
The light from SN1987A first reached us on February 23, 1987, and its brightness peaked in mid May, almost 3 months later.
However, every source that I can find states that it normally only takes a ...
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Get orbital period of exoplanet from light curve using astropy.timeseries
I am using astropy and I would like to calculate orbital period of an exoplanet by its star's light curve. I follow tutorial in astropy docs and I use data from Kepler in Nasa Exoplanet Archive.
...
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Confused about rubber sheet analogy!
How to resolve confusions on the rubber sheet analogy of the spacetime curvatures?
I am a newbie to spacetime curvature. I have watched several youtube videos on Einsteins GR and spacetime curvature ...
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What caused instant jumps and exactly flat periods in Kepler's light curves?
Last 65 days of Kepler's light curve for the infamous KIC 8462852 star is shown below from the published paper's graph. Skip the dips here, I wonder about two other features:
Day 1559, during a ...
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How do you tell if a variable star is periodic or not by its light curve?
I have light curves for a particular star. I'm able to construct a periodogram of the stars' light curve, a plot of the power of the light curve vs. the signal's period. For a nonperiodic but ...
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Sudden spikes on the light curve of a Quasar from K2 mission
I obtained the optical light curve of 3C 273 QSO from the MAST repository off the K2 mission and plotted it by making the FITS into a CSV file through Pandas dataframe and plotting the obtained ...
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On the "periodic" lightcurves of Active Galactic Nuclei
So apparently they are all lightcurves of (likely candidates) Active Galactic Nuclei and in some way or the other they all appear to be periodic:
I'd like to know the reason for this and the ...
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Light curves for Chandra
I am working with Chandra data. I only have the corrected PI files for the sources. Is there a way to plot the light curve from this PI file. I wanted to extract the color magnitude ultimately.
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How do I get temperature and diameter from a light curve?
I recently learned that short-period pulsating stars vary in diameter and temperature when they pulsate. If I have a light curve for such an object, is it possible to calculate its diameter and ...
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creating asteroid light curves and analysing them
I came across the video Tutorial: Creating a Lightcurve of a Minor Planet linked below by Tycho Tracker, which is software that builds an asteroid light curve from raw images and analyses it to obtain ...
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Has the new type II supernova SN 2023ixf's subtype been determined yet, and is a tentative light curve possible? Is it still getting brighter?
Wikipedia's article on SN 2023ixf begins:
SN 2023ixf is a type II (core collapse) supernova located in the Pinwheel Galaxy (M101). It was first observed on May 19, 2023 by Koichi Itagaki and ...
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How much time do I have left to easily spot the recently brightened Recurrent Nova RS Ophiuchi with binoculars and mild light pollution?
Excellent answers to Binocular-friendly star map to find the Recurrent Nova RS Ophiuchi? provide some helpful maps for circa 8° FOV binoculars, but due to spatial and potential meteorological ...
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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 ...
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Comprehensible full manual for bolometric light curve reconstruction
Could anyone point me to some manual or tutorial, possibly step-by-step one, on reconstruction of (quasi-) bolometric light curve using UBVRI-photometry data?
Both links and names are fine for me.
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What could successive double dips in the light-curve mean?
I was going through some analysis of the TESS light-curve data and I stumbled upon an interesting example (see below figures, where the blue line is simply a moving average), where the light-curve ...
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Calibrating raw photometric measurements
So I have a photometry data sourced from Solar Mass Ejection Imager's (SMEI) server as an ‘add-on data’ for my point source of interest (a variable star) with a 104 minute cadence. However, it’s not ...
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Fourier analysis of exoplanet transit to determine the number of planets in the system
Although I think that this can be done by simply looking at the transit graph, I was wondering if a Fourier transform of a transit (basically transforming transit depth/amplitude vs time graph to ...
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How to obtain luminosity distance from a light curve
I have some light curve data of a SN Ia from which I want to find the luminosity distance $D_L$.
How can I do it mathematically?
I'll then try to implement the answer using Python.
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Obtaining the Light curve of a a Quasar
So, I am relatively comfortable with handling $\textit{FITS}$ files and hence I choose Python for the following operation.
The thing is that I need to analyse some Quasar light curves and hence I went ...
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Pair together light curve and radial velocity data of specified star
I would like to create a web application that works with light curves and radial velocities of stars with exoplanets. I found a NASA bulk data download with both light curves and radial velocities (it'...
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How does the size of a naked black hole effect its photon sphere?
What effect does the size of a black hole have on the size or density of the photon sphere and it's proximity to the horizon?
For example: A person is in space looking at 2 black holes, one of them ...
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How does one actually fold a light curve?
I'm studying the variable stars (periodic variables with brightness changes repeating over time), and to examine the shape of the light curve it is useful to fold the data points at this period and ...
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What determines how accurate a particular method is at finding the period between Lomb-Scargle and String Length Minimization?
I've been using the Lomb-Scargle and String Length Minimization methods to find the periods of various astronomical objects with unevenly spaced data. I wanted to see if I could find any patterns ...
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Converting Light curve to Luminosity
So I'm currently working around a specific variable star, α Ori and I want to determine it's luminosity...I do only have the light curve (driven from V-optical photometric band - Johnson V from AAVSO)....
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How do I phase fold the light curve for a variable star?
I have some observational data for a star where I've done aperture photometry to get a partial period. I understand that you need to use other techniques to estimate a period for stars whose period is ...
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Binning a Phase Folded Lightcurve
How do I bin a messy phase folded lightcurve? This is one of the phase folded generated plots for a variable star. I plotted the phase using the period extracted by Lomb-Scargle Periodogram algorithm. ...
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What does a fitted curve for the period of a variable star, tell me about the star?
If I have enough data of a variable star to make a light curve for it's whole period, and If I fit a function to that light curve, can that fitted function tell me anything about the properties of ...
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Obtaining the Flux-Time plot for a Quasar
As a follow up question to Obtaining the Light curve of a a Quasar, I wish to know how to obtain a Light curve for a quasar observation like this data set over here.
Is there an archival repository ...
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How to recognize exoplanet transit
I am using Python package lightkurve for exoplanets searching by the transit method. When I download light curve of some star and apply periodogram, I find frequency and power of periodic components ...
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What are these data in light curve generator
I'm generating light curves for some variable stars on the AAVSO website (see https://www.aavso.org/lcg ) . I can choose what type of data must be plotted. Can you explain what they are?
Thank you in ...
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Python: Find brightest pixel in fits-file and ignore brighter artefacts
I have 4000 fits-files images from SPITZER, each containing the same star over a time period. Each image is a photmetry cube of 32 pixel * 32 pixel * 64 consequent time frames. I need to look through ...
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Using data from the Fine Guidance System (HST)
Has anyone been able to successfully use data from the Hubble Space Telescope's fine guidance system in order to create light curves?
I found a bunch of older papers that reference this instrument, ...
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Finding the uncertainty in period for String-Length Minimization calculation
I wrote a Python script that calculates the period of an unevenly sampled data set using the String-Length Minimization method.
You can read about that method here: A period-finding method for sparse ...
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Which value of the apparent magnitude do I use from a Supernova light curve
I am trying to get the distance modulus from a light curve of a supernova and obviously the apparent magnitude changes with time. Not only that but there are so many filters with different mags.
So my ...
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Simulating Light Curve with the Timmer & Koenig method in Python
How can I simulate the light curve using the Timmer & Koenig method in Python with error bars in each counts generated by that method. I have used Astro ML but it doesn't show the error in the ...
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Should I fit a function to this lightcurve?
I am creating a light curve for the duration of a binary system in order to find out the duration of the eclipse. I am unsure as to whether to fit a function to the data (is it appropriate) as by ...
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How to model blazar light curves
I have SED data spanning over a couple of days and I'm able to find the parameters of the SED (R, B, break energy,...) using least squares method. My question is how to model light curves (with t_acc, ...
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A basic question about light curves
I'm new here, so if I've done anything wrong, please let me know.
I've been taking a look at some photometry data collected from TESS, and I encountered this light curve:
(please ignore the blue and ...
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Finding the precession period of folded light curves
I was supposed to find the precession of a certain frequency in a time series. I tried breaking down the time series into smaller intervals and folded them over the average frequency I'm interested in....
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Depth of primary and secondary minimum in a light curve
How can I explain approximately the same depth of primary and secondary minimum in light curve?
I observe star HD 36486. I tried filters MOST and BRITE.
Is it related with photometric filter? When ...
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Sinusoidal Light curve of an eclipsing binary [closed]
This light curve seems really weird to me, I'm used to seeing light curves where the barycenter is a straight line. It either stays at a place, moves at a constant speed or slowly increases its speed. ...
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Could Tabby's star be beamed by a neutron star's jet causing irregular star spots?
There have been some other questions here about what might cause the light curve dips of star KIC 8462852 as observed by Kepler Space Telescope. Here's one I haven't heard before:
Could it be that a ...
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Where can I download processed data of the Kepler telescope?
I search for lightcurve Kepler data: time $t_i$, flux $F_i$ and measurement uncertainties $\sigma_i$ I need processed data (after removing trends, normalized, etc.). Where can I find it?
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Calculate mass of exoplanet from transit method
Is there any way to calculate (or at least estimate) mass of an exoplanet from transit method? I know that mass can be calculated with radial velocity method, however I would like to create program ...
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Calculate depth and duration of exoplanet's transit using Python, astropy or lightkurve
I am creating a program for the analysis of exoplanets in Python using Astropy and Lightkurve libraries. I have light curve of specified star and I would like to calculate depth and duration of planet ...
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How can I estimate the initial luminosity of a SNIa given initial mass of Ni-56?
The initial portion (and peak) of a SNIa's light curve is powered by the $\beta$-decay reaction:
$$ ^{56}Ni \rightarrow ^{56}Co + e^+ + \nu_e + \gamma $$
Supposing we know how much Ni-56 is created in ...
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How Can I interpret this particular light curve without reading data on the side
There is only one dip in flux recorded. How can I interpret this particular light curve and find planetary radius
https://exo.mast.stsci.edu/exomast_planet.html?planet=55Cnce
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relative weighting in light curves fitting with data
I want to use Eclipsing Light Curve (ELC) Code for the first time to model light curves and radial velocity curves of binary stars. My data sets are of different numbers of data points. I need to do ...
