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Questions tagged [astronomy]

Astronomy (from Greek: ἀστρονομία) is a natural science that studies celestial objects and phenomena. It applies statistics and other mathematics, physics, and chemistry in an effort to explain the origin of those objects and phenomena and their evolution.

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Do they use some Bayesian-frequentist amalgamate in astrophysics?

Below is a figure (highlighting is mine) from Madhusudhan et al. (2023). It caught my attention in a recent video by Becky Smethurst, where she explains some more context (but that's not necessary for ...
Durden's user avatar
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How to train with convLSTM2D on variable input shape?

I am classifying time series of 72x72 images in 4 filters (just like RGB). Things work well ...
user43280's user avatar
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3 votes
0 answers
50 views

How do I analyze the statistical differences between the slopes and r^2 values of the trendlines for more than two groups?

I'm currently a high school senior working on an astronomy research project, and am having trouble determining if there's a special kind of statistical analysis that I need to perform on my data. I'm ...
The Bookwyrm's user avatar
2 votes
1 answer
77 views

Could classical astronomic discoveries be made using ML?

Imagine that prior to the time of Copernicus, scientists could run machine learning algorithms (somehow). Would it be possible to discover the truth of the geocentric model with their use? Would the ...
Sam's user avatar
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1 vote
2 answers
40 views

Dataset with two unique trends?

I have a scatterplot displaying one data set that, at first glance, has a weak negative correlation. Upon further inspection, however, it appears that the data set shows two stronger linear trends ...
houseofguitars's user avatar
2 votes
0 answers
51 views

Measure of goodness of polynomial fit at specific points or weighted analysis?

I have some astrophysics data of "particle density vs orbital position" of a moon that emits a lot of particles. My research deals with the intensity of the scattered light which is ...
Claudia's user avatar
  • 21
2 votes
0 answers
313 views

Converting a chi2 to a sigma value

I am working in astronomy. I fit a theoretical model to some data. The model takes input parameters (like the mass and age) and produces some outputs that I compare with the data. I measured the ...
rhombidodecahedron's user avatar
0 votes
0 answers
42 views

Bayesian or Frequentist goodnes of fit: depends on the data?

I'm working with the data of the real masses of exoplanets published in the catalogues (NASA, exoplanet.eu). Those catalogues update almost everyday by adding new exoplanet data or correcting some of ...
Fabio's user avatar
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0 answers
84 views

How to compare distributions with errors on the data points?

Here's a mock set-up of my problem: I have two non-normal probability density distributions (PDFs), $A$ and $B$. Distribution $A$ has error measurements for each data point while distribution $B$ ...
astrobrez's user avatar
0 votes
0 answers
299 views

Sampling from an infinite population

SAMPLE SIZE I am sampling astronomical data and measuring clusters of galaxies (within a range of 100 megaprsecs) as nodes in a complex network, where k is a metric ...
8-Bit Borges's user avatar
3 votes
1 answer
136 views

How to interpret this scatter plot?

I am simulating a population of binary stars by generating many samples of orbital parameters. I'm investigating the relationship between the inclination of the orbit and the fraction of the ...
Sofia Splawska's user avatar
1 vote
0 answers
132 views

biplot of PCA data gives very unusual

Very much a new at data analytics, with some functional understanding of statistics. I was referred to this site from elsewhere. I am looking at ca. 1000 optical spectra, data available from the ...
Screamh's user avatar
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1 vote
0 answers
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Error Propagation through Iterated Functions (variable star data)

I'm an astronomer trying to smooth variable star data, and one way I'm doing this is using a 7-point, second-order Savitzky-Golay filter. I iteratively apply the filter 51 times (i.e. I apply the ...
mknote's user avatar
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2 votes
1 answer
51 views

Which is the error of a value corresponding to the maximum of a function?

This is my problem: I use data observed with MUSE (which is an astronomical instrument provides cubes, i.e. an image for each wavelength with a certain range, link ) to extract a measure of redshift. ...
Giuseppe Angora's user avatar
3 votes
1 answer
393 views

Time Series Analysis and Forecasting of Astronomical data having a sinusoidal trend

I have data of an orbital parameter of a satellite for 456 days. I am treating this data as univariate time series data and wish to use time series models to forecast future values. However, this data ...
aaliqureshi's user avatar
2 votes
0 answers
68 views

Python Machine Learning: Measuring confidence in individual classifications

I am pretty new to machine learning. I am currently using sci-kit learn's DecisionTreeClassifier and RandomForestClassifier to look at astronomical data. It takes in a number of parameters and tries ...
ZacharyC's user avatar
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33 views

Goodness-of-fit test for multiple components?

I'm running model fits on some simulated data to check my ability to recover my input when I add some noise to it and resample it. The data is a set of spectra that has a galaxy component and a quasar ...
Paul C's user avatar
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3 votes
2 answers
640 views

Should I use a paired sample t-test to compare two methods of measuring absorption lines?

Background I'm doing a research project in astronomy and measuring equivalent widths of absorption lines using Gaussian fits from a star's spectrum in order to determine the star's chemical ...
Evgenii's user avatar
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1 vote
0 answers
128 views

How does one compute the posterior odds ratio between two models

Apologies if this question has been asked before but I couldn't find anything that matched my problem. I have some astronomy based data sets and wish to find which of three models fits the data the ...
Tech's user avatar
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8 votes
1 answer
237 views

Is a visual estimate of homoscedasticity rigorous enough?

As part of my research in astronomy (quasar magnitudes at various wavelengths), I've been producing graphs such as the following: The bottom plot on each graph shows the distribution of the residuals ...
Jim421616's user avatar
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2 votes
0 answers
47 views

The probability of photon collision

I was reading a textbook and I couldn't figure out something that seemed really obvious: Assume that the space is uniformly and randomly filled with stars, and the mean radial distance between the ...
Matina's user avatar
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3 votes
1 answer
661 views

Advice to find faint periodic signals in time series data using deep learning methods

We are using few petabytes worth of time series astronomy data. The general aim is to find very faint periodic signals within it. Our current method of processing this data is to do a Fast Fourier ...
Vishnu's user avatar
  • 141
0 votes
1 answer
412 views

How to deal with changing variance in data sets

I've done an entry level stats course, so my knowledge is very limited in regards to this topic. I'm dealing with large datasets (~3000-9000 data points), and trying to pick signals out of the noise ...
Pulchritude's user avatar
4 votes
1 answer
335 views

Bayesian inference for probability of finding extra-terrestrial intelligent life as more negative evidence is collected

Consider the problem of estimating the number of discoverable extra-terrestrial civilizations (in our galaxy, say), or the related problem of estimating the probability of discovering such a ...
David G. Stork's user avatar
1 vote
1 answer
801 views

Machine Learning for optimization of configuration file

For my master's thesis I am using a 3rd party program (SExtractor) in addition to a python pipeline to work with astronomical image data. SExtractor takes a configuration file with numerous parameters ...
Christoph Pohl's user avatar
1 vote
2 answers
468 views

Learn Bayesian inference applied to astronomy / astrophysics?

I'm looking for resources (books, articles, sites, etc.) to learn about Bayesian inference, but specifically applied to astronomy and astrophysics.
1 vote
0 answers
41 views

What is the point of using an initial estimate when sigma-clipping data?

I am reading a paper that is discussing sigma clipping some velocity data, lets call it a set $V$, and it says: The center at each iteration of the $3\sigma$ clipping is the biweight average, and $\...
pretzlstyle's user avatar
6 votes
0 answers
209 views

Statistics behind gravitational waves discovery [closed]

The recent gravitational waves result is a stunning feat for both physics and engineering. I suspect there may be much to admire on the statistics side as well. For example, the original paper states: ...
half-pass's user avatar
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1 vote
1 answer
425 views

How to check if two results are consistent

I'm looking at an astronomical object. In one observation, it does something (not relevant what :) 2199 times out of a possible 2936. In another (later) observation, it occurred 2094 times out of a ...
user1551817's user avatar
  • 1,233
2 votes
1 answer
2k views

Method for fitting censored data in R

I have 320 data points - each has a redshift and a turnover-frequency, and I want to fit a correlation between them (a linear fit). However, 120 of the turnover-frequency values are upper limits. As ...
Matt Majic's user avatar
4 votes
1 answer
1k views

Python Astronomy Censored Data in Lifelines [duplicate]

I am trying to find a correlation between a given data set containing redshifts and turnover frequencies (I have a list of 320 galaxies, and the redshift and turnover frequency (a turnover frequency ...
Matt Majic's user avatar
1 vote
0 answers
1k views

How to pick the "sigma" when sigma clipping?

In astronomy (and I'm sure in other places as well) it is very common to use sigma-clipping as the outlier rejection scheme. The idea is that you regress the data, subtract the fit from the points, ...
rhombidodecahedron's user avatar
5 votes
1 answer
171 views

Why are there more bayesians than frequentists in astrophysics?

I heard somewhere that in astrophysics, there are more bayesians than frequentists (although in general, I think that bayesian community is smaller). Is there something special about "astro" data what ...
sitems's user avatar
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10 votes
2 answers
2k views

History: the role of statistics in astronomy

I recently boldly claimed in front of a group of fairly smart eighth grade students that astronomy contributed greatly to the foundations of statistics and many statistical concepts were invented for ...
Rob Hall's user avatar
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4 votes
3 answers
294 views

Which test is better suited to compare averaged versus single data sets

I have a light curve, that is photon count rate versus time, of an astronomical object. These data are periodic since the source signal is periodic. I can fold the data with the period and obtain an ...
Py-ser's user avatar
  • 451
1 vote
0 answers
134 views

Calculate the number of trials to distinguish between 2 models

This sounds like a problem that has to be well known, but I can't find a good answer. I have tried another forum before I realized there was a stackexchange stats site. So here goes ... I have two ...
Jimbo's user avatar
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