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)

Filter by
Sorted by
Tagged with
3
votes
1answer
116 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 ...
3
votes
1answer
23 views

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 ...
5
votes
0answers
46 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 ...
4
votes
1answer
35 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 ...
8
votes
1answer
62 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. ...
4
votes
1answer
42 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://...
2
votes
1answer
46 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 ...
2
votes
0answers
27 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 ...
4
votes
1answer
84 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 ...
3
votes
1answer
240 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 ...
3
votes
1answer
68 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 ...
3
votes
1answer
61 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 ...
6
votes
1answer
245 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 ...
2
votes
0answers
59 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 ...
2
votes
0answers
48 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–...
2
votes
0answers
109 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 ...
1
vote
1answer
133 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 ...
19
votes
2answers
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 celstial dome), by brightness? I want to know if they are uniformly distributed. For example, ...
1
vote
1answer
42 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 ...
2
votes
1answer
44 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 ...
3
votes
1answer
63 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 ...
2
votes
2answers
123 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 ...
3
votes
1answer
123 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,...
1
vote
1answer
37 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 ...
3
votes
1answer
93 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 ...
1
vote
1answer
45 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 ...
4
votes
1answer
180 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 ...
1
vote
0answers
62 views

Detecting the Chicxulub impactor, right now [duplicate]

Say an asteroid identical in all ways to the Chicxulub impactor (size, mass, materiel, orbital type, etc) was about to hit us. (Again!) As of exactly early 2018, given our known instruments and ...
2
votes
2answers
115 views

Stuck with SDSS data [closed]

I want to do project on astronomical dataset. Regarding that project, I try SDSS who give public dataset but it is quite complicated for me. I gone through public dataset and downloaded some .FITS ...
3
votes
1answer
363 views

360 degree equirectangular projection of all naked eye stars with precessional motion for simulating

For many years now I've been using Voyager sky simulator by Carinasoft. The projection selections are great, but Equirectangular doesn't seem to one one of them. Is there a program out there that does ...
4
votes
1answer
1k views

How do I create a galaxy stellar mass function?

Suppose that I have an array of stellar masses of tens of thousands of galaxies, and that I also already know what the total "survey volume" is (in Mpc^3) within which all of those galaxies are ...
4
votes
1answer
100 views

What complementary observation campaigns have looked at Kepler's field of view?

It seems to be common practice to double up observations. For example, shortly before New Horizons flew by Pluto, several of its moons were discovered by telescopes as a concerted effort was put in ...
4
votes
2answers
149 views

What is the largest (angular) dark area in the sky?

Question Within our current knowledge, what is the largest (circular, say) area in the sky which is empty/dark? I'm thinking in terms of angular size. Motivation I was wondering what was the ...
1
vote
0answers
65 views

Stellar catalogues stars in specific sky regions – without downloading the catalogs

I’m interested, to give a scientific realism to a project I’m working on, in finding a picture of all stars belonging to a star catalogue such as Tycho 2 or Hipparcos for some very specific sky ...
1
vote
0answers
330 views

Sloan Digital Sky Survey (SDSS) HDU `or_mask` - what does it mean exactly?

I'm looking at the Sloan Digital Sky Survey data. I'm primarily using the flux data, from the documentation I see the first extend (HDU 1) has flux, ...
1
vote
1answer
43 views

Storm with lightnings and no thunder [closed]

Last evening I assisted in an interesting phenomenon in my region (Eastern Europe). It was a dark sky with heavy rain and blinding lightning (which struck every 5 seconds or so), but NO thunder at all....
3
votes
2answers
172 views

Are 3D coordinate data from Sloan DSS-III available & easily accessible to non-pros?

Of course the newly announced SDSS-III data and maps from the Sloan Digital Sky Survey with 1.2 million objects, along with all previous data sets are openly available, and I'm sure there are many ...
1
vote
1answer
410 views

Create a signal to noise map from heatmap

Recently, I obtained my heatmap from a sky survey. But now, I'm trying to get a signal to noise map from my heatmap. My heatmap looks like : My colour bar indicates the number of stars per pixel (I ...
1
vote
0answers
60 views

SDSS ImgCutout webservice returns black image for dr12

The SDSS (Sloan Digital Sky Survey) ImgCutout webservice should return jpeg images for a given field that is defined by the parameters. The service can be tested here: http://skyservice.pha.jhu.edu/...
2
votes
1answer
691 views

Definition question: continuum-subtracted spectrum

What is the exact definition of a "continuum-subtracted spectrum", such that one finds in SDSS spectra? http://classic.sdss.org/dr7/dm/flatFiles/spSpec.html#specmask Is there a definition somewhere?...
3
votes
1answer
142 views

Sloan digital sky survey galaxies

I am trying to get some data from the Sloan digital sky survey (SDSS). This task turned out to be challenging for me as someone with only little knowledge about astronomy and maybe someone here can ...
13
votes
3answers
2k views

How to detect emission lines in optical spectra?

Is there any handy module to detect emission lines in a spectrum like one we get from the Sloan Digital Sky Survey (SDSS)? You can see there are many emission lines like Ha,OI in the spectrum below. ...