Questions tagged [data-analysis]

Analysis of data is a process of inspecting, cleaning, transforming, and modeling data with the goal of discovering useful information, suggesting conclusions, and supporting decision making.

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How can I join as contributor to open source code on GitHub? [closed]

I want to join as a contributor, e.g., making pull or merge requests on GitHub, in an existent open source astronomy project. How do I start? What's the typical scenario? Writing directly to the ...
nuwe's user avatar
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1 vote
0 answers
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How to determine semiamplitude from Julian Date data?

How could I determine semiamplitude from these data for NGC300 X-1 without fitting, only with data of phase and JD? This is a common problem for exoplanets, X-ray binaries and other general binary ...
riemannium's user avatar
1 vote
0 answers
36 views

On building a compatible pipeline for astrometry using both Gaia or Vera-Rubin's data

As the title states, I'm considering building a pipeline for astrometry to analyze Gaia and Vera Rubin's data. As, being honest, I have little experience with astrometry, I'm not sure if this is (or ...
nuwe's user avatar
  • 797
2 votes
0 answers
94 views

What are These Strange Lines in my Catalog Data?

So, I'm graphing the specific star formation rate (star formation rate per unit mass) over redshift of various different catalogs. However, I keep running into these strange lines that make me ...
Ataaamic's user avatar
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5 votes
1 answer
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How to Determine Absolute Magnitude of a Galaxy using HST FITS Image

I'm attempting my first serious research project but due to... various circumstances, I am going to mostly be solving problems like this on my own with minimal outside help. As for the actual problem, ...
Ataaamic's user avatar
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6 votes
1 answer
796 views

Could an hypothetical hidden black hole companion to the sun be revealed by proper motion data?

If the Sun were in a binary star system with a black hole companion, the Sun would be orbiting the black hole, and this should be reflected in a change in the observed proper motion of nearby stars. ...
tutizeri's user avatar
  • 357
1 vote
1 answer
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Moon's libration from Mathematica data

Wolfram Mathematica provides "TransitTime" option (for the Moon in particular). Knowing this time moment, you can get the position of the moon at upper culmination (for example, for each day ...
lesobrod's user avatar
  • 123
1 vote
0 answers
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CMB maps analysis (Planck, ESA, FITS)

I wanted to analyze Planck mission FITS files and was wondering about the parameters. So the map uses color coding for temperature-based anisotropies right? So the maximum angular resolution is ...
user2820052's user avatar
4 votes
2 answers
238 views

Formation of spacecraft instrumentation [closed]

List of spacecraft instruments are selected to meet a mission's science goals. Let's take New Horizons as an example and study the composition of Pluto's atmosphere, the shape and geological ...
dtn's user avatar
  • 705
2 votes
1 answer
64 views

Calculating intensity of moonlight per unit area

I have a photodiode that can measure intensity in picowatt to milliwatt range. I have a telescope of 5 inch diameter. I want to calculate the intensity of moonlight received by this area? This will ...
Tumpa's user avatar
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4 votes
2 answers
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Radio Astronomy Data Handling (Filtering What One Needs)

Suppose we have some radio astronomy data for some specific moment (not a time series). Can we, using some computer program, filter out and get, say, only the data (EM radiation), whose sources are at ...
avpol's user avatar
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How can I better align stamps from Hubble images?

I am trying to do difference imaging with Hubble ACS/WFC images and have been using TweakReg to align images and cutout stamps. The problem is that residuals haven't been great and I'm looking for ...
cassandra's user avatar
2 votes
0 answers
28 views

Sloan Digital Sky Survey - Obtaining Spectral and Photometric Datasets

I am working on a soft computing (fuzzy logic), genetic algorithm, explainable AI (XAI) classification system for astronomical objects from the Sloan Digital Sky Survey. The dataset I am currently ...
todd45040's user avatar
2 votes
0 answers
64 views

How can I compute reasonable errors on my Gaussian fits to the observed strong optical lines of interest?

I'm fitting Gaussians to optical lines spanning from H-beta to Sulfur using Astropy's Gaussian (https://docs.astropy.org/en/latest/api/astropy.modeling.functional_models.Gaussian1D.html) model with a ...
Astroturf's user avatar
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Bad syntax for region SIMPLE -- dmextract CIAO 4.15

I am trying to perform a radial profile analysis using Chandra's CIAO 4.15 dmextract function but keep getting the following error: "bad syntax for region SIMPLE". I cannot find any relevant ...
adastra2001's user avatar
1 vote
1 answer
112 views

How to get star position from the Gaia data set?

I’m trying to recreate the Milky Way as a particle system inside Houdini, and I wanted to explore using the Gaia data as a starting point. I’ve downloaded an example source file from the data set but ...
kinkersnick's user avatar
2 votes
1 answer
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Unusual amount of white dwarfs in star clusters in my analysis

I'm trying to plot H-R Diagrams of open clusters using data from Gaia DR3. My workflow is something like this: Plot apparent magnitude vs log(distance) in pc. An overdensity would indicate the ...
Ambica Govind's user avatar
2 votes
0 answers
42 views

ds9 configuration issue

I'm trying to use DS9 for X-ray image analysis. Before that I have to configure it for use, I need to click on option using web proxy. Beside use internal web browser checkbox there should be another ...
ALIEN X's user avatar
  • 21
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0 answers
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What are examples of spatio-temporal data sets such that subjects are observed only once and are, thus, indexed in time only once?

What are examples of spatio-temporal data sets such that subjects are observed only once and are, thus, indexed in time only once? Here's a hypothetical example in the ecology realm: consider a tree's ...
Ron Snow's user avatar
  • 101
3 votes
2 answers
88 views

How to construct optimal Wiener Filter?

I am trying to construct a Wiener Filter, to filter the ratio of the peak from the cross-correlation function, between a galaxy spectra and a template spectra, with the peak of the auto-correlation ...
trynerror's user avatar
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0 answers
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What courses should one take for working towards Astronomy from an AI / Data Analysis perspective?

Note:- This is a suggestions seeking question As a prospective student about to embark on pursuing the MEngg. in Applied AI program, I am eager to align my education with my passion for Astronomy. I ...
Hacker1's user avatar
0 votes
1 answer
188 views

What am I doing wrong in this ppxf application?

I am trying to derive the kinematics of a galaxy spectra. To test my results I want to implement the Penalized Pixel Fitting method. For the galaxy spectrum I use a central line with sufficient S/N. I ...
trynerror's user avatar
  • 839
2 votes
1 answer
243 views

How can someone take narrowband data from an OSC narrowband filter

To those who aren’t aware, an OSC narrowband filter is a filter with multiple band passes, for different emission lines. These can include a combination of Hα, Hβ, OIII, SII, and other emission lines. ...
Topcode's user avatar
  • 166
4 votes
1 answer
158 views

Where can I get raw photos of planets clicked by HST, Voyager 1 and 2, Cassini for Saturn and Galileo for Jupiter?

I intend to process RAW images of planets clicked by HST,Voyager 1 and 2, Cassini and Gallileo spacecrafts using a few softwares. I am in search of where I can get these raw images from.
Dhruv Nayak's user avatar
3 votes
1 answer
112 views

Convert image from Jy/sr to Jy/pix

I want to convert the units of an image from Jy/sr (Janskys per steradian) to Jy/pix and I know the pixel scale in arcsec. The way I do this, in python, is the following: ...
Sketos's user avatar
  • 31
3 votes
1 answer
72 views

Solar-winds: public NOAA data

I was searching for interesting data from space recently, and stumbled onto https://www.swpc.noaa.gov/. The long and short is that they offer some interesting solar wind data Of particular interest to ...
Kai Harris's user avatar
2 votes
0 answers
58 views

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 ...
Zachary Kennedy's user avatar
9 votes
2 answers
141 views

What's a good example of published astronomy pipeline coding libraries

I am a software engineer and I am preparing a presentation to aspiring astronomy PhDs on how to use best-practice software engineering when publishing code (such as include documentation, modular ...
nsimplex's user avatar
  • 191
1 vote
1 answer
77 views

Do astronomical datasets exist that receive duplicates or are there multiple datasets that contain the same entities (stars)?

I am currently doing my PhD in computer science, and I have almost no astronomical knowledge. I am currently researching on duplicate detection in databases (so detection of multiple entries referring ...
Lasklu's user avatar
  • 21
0 votes
1 answer
98 views

2D Galaxy Spectrum taken by long-slit-spectrograph

I have the 2D data (shape(1125,2058) taken by a long slit spectrograph, which looks as follows: The y-axis corresponds to the distance from the center, where the center is at the most bright green ...
trynerror's user avatar
  • 839
14 votes
2 answers
3k views

How did asteroid (7482) 1994 PC1 get its "face"? Is it reconstructed from optical or radar imaging, or something else?

(Image sources linked below) NPR's March 10, 2023 Newly found asteroid has a 'very small chance' of hitting Earth, NASA says includes an image of what looks like a computer reconstructed 3D surface of ...
uhoh's user avatar
  • 31.3k
12 votes
2 answers
738 views

How has the resolution of astronomical spectrographs improved over time?

Is there something like a Moore's law for spectral resolution? Maybe a chart from which one could extrapolate?
2080's user avatar
  • 1,858
1 vote
0 answers
42 views

Best resource for exoplanet statistics?

While the number of detected exoplanets is still low, is there a model that, considering the number and duration of made observations, and the fact that (non)detections depend on orbital plane ...
2080's user avatar
  • 1,858
2 votes
1 answer
279 views

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 ...
Saturn.'s user avatar
  • 49
2 votes
2 answers
230 views

Reduced chi square value

I am currently plotting a continuum of observed data. I need to check the effectiveness of the fitted continuum with the reduced chi-square method. Ideally, should the reduced chi-square value ...
summer's user avatar
  • 31
11 votes
3 answers
2k views

What is the most common activity of astronomers in the JWST? [closed]

I am no astronomer. I am a computer scientist. I recently read this article: JWST has changed the speed of discovery, for better or for worse - Astronomers are working at a furious pace to analyze and ...
Demis's user avatar
  • 883
3 votes
1 answer
88 views

How can we make sure that it is physically the same source when we do cross matching?

When we go through multiple astronomy catalogs, we often do Cross-matching. We compare the position parameters $(\alpha, \delta)$ of different sources (galaxies, quasars, etc.) in the equatorial ...
Chang's user avatar
  • 31
2 votes
2 answers
84 views

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 ...
Zachary Kennedy's user avatar
1 vote
1 answer
101 views

Database for distant stars

I'm looking for a database of stars that lists as many of the known stars as possible. Ideally, I'd like it to have information on the radius of the stars, the distance from the earth and the ...
EmeraldThunder-'s user avatar
4 votes
1 answer
1k views

How does one convert between Modified Julian Date (MJD) and a standard (mm/dd/yr, hr:mm:ss)

I looked online and couldn't see an actual formula or anything, so I figured I'd ask here. If I had an MJD like the following: 59145.6678 How would I convert that to a month, day, and year with the ...
Zachary Kennedy's user avatar
2 votes
0 answers
105 views

Where to get MOST data?

Where to get MOST data (light curves), please? Does a database or a list of objects that were exist? I mean MOST spacecraft.
Anna-Kat's user avatar
  • 505
3 votes
0 answers
23 views

What Simple and Multiple Linear and Logistic Regressions Would Be Valuable for a Celestial Mechanical Data Set for Exoplanets with Density?

I have created a celestial mechanical data set for exoplanets with density values (https://github.com/tslever/Tom_Levers_Git_Repository/blob/main/UVA/2--Linear_Models_For_Data_Science/Project_2/...
Tom Lever's user avatar
  • 191
1 vote
0 answers
73 views

Tables or software for some astronomical data

Recently I saw a beautiful (but not rare) phenomenon - Jupiter was "directly above" the Moon, that is, they had the same azimuth and a small difference in altitude. I would like to see on ...
lesobrod's user avatar
  • 123
6 votes
1 answer
80 views

Other than Lomb-Scargle Periodograms and String Length Minimization, what other methods can be used to find the period of unevenly spaced data?

I'm doing some research into how different methods of finding the period with unevenly spaced data compare with each other. So far, I've looked at the Lomb-Scargle and String-Length Minimization. I ...
Zachary Kennedy's user avatar
12 votes
0 answers
218 views

What 1° x 1° region is the optically darkest patch in the sky?

What 1° x 1° region of the night sky has the lowest flux of light? (considering the typical visual/luminance filter range, approximations using other filters/bands are acceptable, but should be in the ...
2080's user avatar
  • 1,858
4 votes
1 answer
368 views

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 ...
Zachary Kennedy's user avatar
2 votes
1 answer
54 views

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 ...
Zachary Kennedy's user avatar
3 votes
1 answer
70 views

How do cross-matching algorithms deal with unequal-sized catalogues?

Let's say I'm using a service like TOPCAT or Vizier's cross-matching service and I'm trying to match the RA and dec of the sources in Catalogue 1, with 100,000 sources, to those in Catalogue 2, with a ...
Jim421616's user avatar
  • 2,498
2 votes
0 answers
76 views

SDSS and DESI - How much variation in sky location?

I am trying to cross match a catalog derived from SDSS-MaNGA(self) with a catalog derived from DESI (Yang+2021). I am using TOPCATs Sky Algorithm, based on RA and Dec similarities to perform the ...
haricash's user avatar
3 votes
1 answer
91 views

How do I create well a weighted black hole mass function?

I'm running a set of simulations to study the evolution of Super Massive black holes. In principle, I have the black hole masses and other property called merger tree weight in Mpc-3 unit which is ...
Matías Liempi's user avatar

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