Questions tagged [sky-survey]

A sky-survey is a general map or image of a region of the sky which lacks a specific observational target, but this tag also applies to surveys of a given class of objects, (e.g. TESS)

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How to obtain the SDSS’s five-part imaging ID number for a list of galaxies whose Ra Dec is known?

I am trying to obtain the FITS file of a few hundreds galaxy from SDSS DR12 Survey. SDSS tries to download the FITS File with the link that contains the information about SDSS’s five-part imaging ID ...
B. S.'s user avatar
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What are radio frequencies sensitive to in galaxies?

Apart from 21cm line studies, radio emissions as well as signatures of different radio sources, do radio frequencies help in the identification of a particular physical structure or presence of some ...
Dhruv Nayak's user avatar
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Are more stars or more galaxies cataloged, currently, and how has the ratio evolved over time?

I recall that there are of order 100 billion stars in a galaxy and 100 billion galaxies in the (observable) universe, or something roughly like that. Since we are IN a galaxy we have an opportunity to ...
uhoh's user avatar
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4 votes
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Sky surface brightness vs magnitude limit visibility

I am wondering how we can calculate the magnitude limit of the celestial object, which could be visible at the given sky surface brightness conditions. We already know that Venus and Jupiter are ...
Geographos's user avatar
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2 answers
118 views

Are there any new/latest/recent radio sky surveys' data release which is publicly accessible?

There are many sky surveys that have been conducted by telescopes in different wavelengths of the electromagnetic spectrum like DSS (Digitized Sky Survey), SDSS (Sloan Digital Sky Survey), WISE (wide-...
Dhruv Nayak's user avatar
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Where can I find MITEoR 150 Mhz radio data?

I was working on the Aladin Sky Atlas v12 software and while working on the radio data, I came across this Radio sky survey that said MITEoR 150 MHz. Initially, I mistook it to be GMRT because GMRT ...
Dhruv Nayak's user avatar
4 votes
1 answer
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"To date we have covered 624 square degrees of sky near to and interior to the orbit of Venus" meaning wrt Asteroid survey Interior to Earth and Venus

CNN's October 31, 2022 ‘Planet killer’ asteroid spotted hiding in the sun’s glare links to Sheppard et al. (2022) A Deep and Wide Twilight Survey for Asteroids Interior to Earth and Venus. The ...
uhoh's user avatar
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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
2 votes
0 answers
43 views

General questions about SDSS

I'm considering doing research on SDSS spectral classification (STAR, GALAXY, QSO) with machine learning for my school dissertation. Not sure if this is an appropriate place for these kinds of ...
Robert Mifsud's user avatar
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What sort of exploratory procedures should be carried out on astronomical data? [closed]

Upon downloading an astronomical dataset such as SDSS DR12 from VizieR, what kind of exploratory techniques should be performed? I start with the basics, like this tutorial, and how much missing data ...
Jim421616's user avatar
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Why was the NVSS(NRAO VLS Sky Survey) conducted at 1.4 GHz continuum?

I am observing the nature of some galaxies looking at their radio images and contours from NVSS. So, the data collected have radio flux at other wavelengths but I am studying it at 1.4GHz. I have been ...
Mirae's user avatar
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Querying VizieR using SQL interface on their website

I'm trying to query http://tapvizier.u-strasbg.fr/adql/?%20V/147/sdss12 using the following query, built by clicking Construct your query and ...
Jim421616's user avatar
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2 votes
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Why are the sky distributions of SDSS DR16 and DR16Q different?

I've downloaded the csv files for SDSS DR16 and DR16Q and made a map of their sky distributions: The coordinates come from: DR16: RA_ICRS and ...
Jim421616's user avatar
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How does SDSS estimate photometric redshift of sources?

I'm looking through the data in SDSS DR 12: ...
Jim421616's user avatar
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LSR and peculiar motion corrections to RAVE survey velocities

I am working towards getting a bunch of halo stars in our galaxy for my thesis. I am doing this with the help of a Toomre diagram and I am stuck. I am using the RAVE survey in conjunction with Gaia as ...
CTZenScientist's user avatar
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99 views

Reasons for extremely high number density of galaxies at low redshift

I am currently analyzing the SDSS data especially in the extremely low redshift area, in order to measure the cosmological statistics. What I mean by extremely low is z<0.1. One peculiarity that I ...
Jun-Young Lee's user avatar
3 votes
1 answer
175 views

What does the celestial sphere look like in thermal IR?

The Space SE question JWST detector heat load asks ...what is the heat load from the collected radiation of the main mirrors on the detector, and how does that vary depending on what objects or ...
uhoh's user avatar
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7 votes
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How close are we to observing all of the sky all of the time?

I was musing on how amateur astronomy is still a heavy contributor to the overall field, and how on any given night there will be plenty of small telescopes pointing into the void and capturing the ...
Ingolifs's user avatar
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11 votes
2 answers
2k views

14,000 square degrees

The DESI Legacy Imaging Surveys says it produces a model of “the 14,000 square degrees of extragalactic sky visible from the northern hemisphere”. But I thought the whole celestial sphere (like any ...
Charles's user avatar
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Calculating comoving volume of 2dF survey

Say I want to calculate the comoving volume in the 2dFGRS survey: I'm using $H_{0} = 70 km s^{-1} Mpc^{-1}$ and the default values for the matter and vacuum density parameters in this calculator (...
ObiDonKenobi's user avatar
1 vote
2 answers
516 views

Could more objects from the Oort cloud with highly elliptical orbits be discovered in the future?

It took the modern astronomy to live to the year of 2014 to discover 2014 UN2711 (sized roughly 100-200 km and now being re-qualified from a comet to mini object), which has "extremely" ...
Alex's user avatar
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What is the most grazing exoplanet transit that has been reported with high confidence?

The abstract of Past, present and future stars that can see Earth as a transiting exoplanet reads: In the search for life in the cosmos, transiting exoplanets are currently our best targets. With ...
uhoh's user avatar
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1 vote
1 answer
132 views

Star visibility above horizon map likewise day & light map or moonlight world map

I am looking for an option to present the given star visibility world map likewise day & night map or moonlight world map like below: Question: Is it possible to generate a map like this for some ...
Geographos's user avatar
3 votes
1 answer
169 views

spider image in Samuel Oschin Schmidt Telescope DSS imagery

I was puzzled by image artifacts that appear in DSS-2 (blue) survey. These images were taken by the Samuel Oschin Schmidt Telescope on photographic plates and later digitized. They are also available ...
axd's user avatar
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1 answer
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Calculating and mapping the best visibility of celestial occurrence

Recently I found a fantastic website in-the-sky.org, from here we can simply pick up any astronomical event and check its visibility in any part of the Globe. For occultations, for example, we have ...
Geographos's user avatar
7 votes
1 answer
156 views

Is the discovery of a "mass gap" black hole by this tiny telescope just plain luck/serendipity or could it be the first of many similar discoveries?

The Kilodegree Extremely Little Telescope is a pair of modest lenses with high quality medium format CCDs attached sitting on oversized mounts in Arizona and Sutherland. These very modest instruments ...
uhoh's user avatar
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4 votes
1 answer
45 views

Are features in the CMB correlated with features in the SDSS map of the most distant galaxies?

This is a follow up to an earlier question to which @pela gave an excellent answer. Apparently the statistics of the length-scales of the CMB fluctuations are similar to those obtained from other ...
Roger Wood's user avatar
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8 votes
1 answer
132 views

Is there any correlation between the Cosmic Microwave Background (CMB) and the distribution of distant galaxies?

The Cosmic Microwave Background (CMB) is remarkably isotropic but does exhibit a distinct dipolar Doppler shift and also much smaller but measurable fluctuations in intensity and polarization. ...
Roger Wood's user avatar
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4 votes
1 answer
358 views

Accessing SDSS server SQL server via python

Is there a way to directly access any of the Sloan Digital Sky Survey servers via SQL via Python? Currently I have been able to run SQL queries from the website they provide (for example https://...
Nickpick's user avatar
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1 answer
97 views

Using SDSS data / finding a catalog

I am looking for a catalog of low redshift galaxies (preferably SDSS) with information on line fluxes and stellar mass. My Google searches keep pointing me to work by the Portsmouth group, so I ...
theWrongAlice's user avatar
3 votes
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41 views

Heat map of portion of the sky visible for a given observatory on Earth?

Reading Calculating area of visible sky I started wondering which portion of the sky one could observe how long given the 3D coordinates of an observatory, and two points in time. In other words, I ...
B--rian's user avatar
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5 votes
1 answer
769 views

What is the completeness of an observation and how do I calculate it?

Many publications write about "completeness". I have a vague idea that it has to do with the ratio of how many sources from an observation are detected and how many sources are actually in ...
kelpfish's user avatar
3 votes
1 answer
971 views

Searching dataset for Constellation detection

I need to develop an Machine Learning (ML) model for predicting constellation seen in a picture taken from a mobile. This I need to develop from scratch. Firstly, I need help finding a database which ...
Harsh Banka's user avatar
5 votes
2 answers
212 views

Basic explanation of baryon acoustic oscillations; what if anything is actually oscillating?

Sci-News' Sloan Digital Sky Survey Collaboration Releases New 3D Map of Universe links to the two videos The eBOSS 3D map of the Universe SDSS releases largest 3D map of the universe ever created ...
uhoh's user avatar
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3 votes
1 answer
123 views

How to plot curvilinear coordinates in the frame of a Cartesian telescope field of view

I am wondering what projection is used to produce plots like this: (Image taken from here, author: NASA/Ames/JPL-Caltech, Image credit: Software Bisque) More generally, I am trying to figure out the ...
NeutronStar's user avatar
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6 votes
1 answer
343 views

Google Sky Rectangle with No Stars

I've been viewing Google Sky, which is quite amazing, and came across a rather expansive rectangle where no stars are visible at 22h13m04.44s 4°59'29.49" (see image below). My only thought is that ...
mkinson's user avatar
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2 votes
0 answers
110 views

Dozens of Oblong Green Objects in Google Sky

In reviewing Google Sky today for the first time, zoomed in at the southern end of the Aquarius constellation, there's dozens of oblong objects, many of which are green. Considering their general ...
mkinson's user avatar
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2 votes
0 answers
50 views

Why do all the stars near this comet show up as four separate dots in a row?

After seeing this tweet about our not-so-new but at least newly-discovered "mini-moon" I scrolled down and saw the tweeted image below. Since the object is the known short-period comet 114P/Wiseman–...
uhoh's user avatar
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2 votes
0 answers
147 views

How are small objects automatically identified and their locations determined in digital images?

I have a large quantity of old digital images of low energy electron diffraction (LEED) patterns that I must process to identify and locate small, sometimes elongated gaussian-like blobs of a few ...
uhoh's user avatar
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1 vote
1 answer
212 views

What is the LSST now? Where does LSST end and Vera C. Rubin Observatory begin?

Space.com's It's Official: Vera Rubin Observatory Named to Honor Dark Matter Scientist says: "We're here today to focus on the major renaming of the facility after a pioneering astronomer, that ...
uhoh's user avatar
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19 votes
2 answers
5k views

Are the stars distributed in uniform distribution, on the celestial dome, with respect to brightness?

Has there ever been a statistical analysis of the distribution of stars in the sky (on the surface of the celestial dome), by brightness? I want to know if they are uniformly distributed. For example, ...
DrZ214's user avatar
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1 vote
1 answer
105 views

Estimating the abundance of type-Ia supernovae using magnitude limited survey

I would like to estimate the fraction of type-Ia supernovae in a magnitude limited survey (only including those supernovae that are brighter than a certain than a given fixed apparent magnitude). I ...
user29126's user avatar
2 votes
1 answer
65 views

Any plans for TESS after it finishes northern sky survey?

TESS has provided the astronomy community with a treasure trove of information. Once TESS completes its one year survey of the northern sky, are there any plans for an extended mission? Just seems ...
user28843's user avatar
3 votes
1 answer
71 views

How to check what telescopes were looking at a certain portion of sky at a particular time?

I have some data that I collected from observations at a specific RA, DEC and I am trying to figure out what telescope surveys were looking at that portion of the sky at that particular time? I am ...
Patrick's user avatar
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2 votes
2 answers
224 views

How does one "use" the Pan-Starrs data?

I've seen that a large block of Pan-Starrs data has been released and is available on-line and how the distributors of the data expect professionals and the general public to use the data in their ...
andyhall's user avatar
3 votes
1 answer
177 views

What is the dimensions of the smallest object detectable by an optical fiber from a specific distance?

Optical fibers are well-known to observe astronomical objects, say, galaxies, to generate massive spectroscopic surveys. The galaxies are often very far from the optical fibers of a telescope. However,...
User's user avatar
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1 vote
1 answer
54 views

What discoveries have come from the DASCH project (Digital Access to a Sky Century @ Harvard)

@astrosnapper's answer to the question Could stellar occultations be used to survey Kuiper belt objects? mentions the TAOS-II project and asteroid occultation measurements (which occur on the ...
uhoh's user avatar
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3 votes
1 answer
116 views

How did TESS scientists choose which stars to observe at a "2 minute cadence" in each field?

The BBC news podcast Science in Action episode New Planet Hunting Mission covers the upcoming TESS mission between 01:00 and 07:15 with Sara Seager, TESS deputy ...
uhoh's user avatar
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1 vote
1 answer
61 views

Is there any way to find out what sky surveys are *currently active?*

I've asked a question about active sky surveys that might intercept a 2% of 4π patch of sky in the next six months and potentially record this dim (+22 to +26 magnitude) object. I've added a bounty ...
uhoh's user avatar
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4 votes
1 answer
252 views

Might the SpaceX Roadster intercept any ongoing surveys?

There are star survey telescopes in space, and on Earth. I don't really know how to begin to know where they will all be looking for the next few months. On the off-chance that someone does, or can ...
uhoh's user avatar
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