Scope

Overview

Data Release 14 is the second data release of the fourth phase of the Sloan Digital Sky Survey. It includes SDSS data taken through July, 2016, and encompasses more than one-third of the entire celestial sphere. The coverage figures below show the sky coverage of DR14 for the eBOSS, APOGEE, and MaNGA surveys respectively (click figure to enlarge).

DR14 eBOSS spectroscopic coverage in Equatorial coordinates (plot centered at RA = 8h.)
DR14 eBOSS spectroscopic coverage in Equatorial coordinates (plot centered at RA = 8h.)
A map of APOGEE plates in DR14. Plates are shown as small circles color-coded by number of observed stars.
DR14 APOGEE-2 spectroscopic coverage in Galactic coordinates (plot centered at Galactic center). New fields in DR14 are circled.
DR14 MaNGA spectroscopic coverage in Equatorial coordinates.
DR14 MaNGA spectroscopic coverage in Equatorial coordinates.

With so much sky measured in so many different ways, questions about the size of the SDSS can be answered in many different ways. This page details the SDSS survey area and provides object counts in Data Release 14 in various ways.


Imaging statistics

Total unique area covered
14,555 square degrees
Total area of imaging (including overlaps)
31,637 square degrees (excluding supernova runs)
Individual image field size
1361×2048 pixels (0.0337 square degrees)
Number of individual fields
938,046 (excluding supernova runs)
Number of catalog objects
1,231,051,050
Number of unique detections
932,891,133
Median PSF FWHM, r-band
1.3 arcsec
Pixel scale
0.396 arcsec
Exposure time per band
53.9 sec
Time difference between observations of each band
71.72 sec (in riuzg order)
Global astrometric precision
0.1 arcsec rms (absolute)
Number of unique, primary sources
Total
469,053,874
Stars
260,562,744
Galaxies
208,478,448
Unknown
12,682
Effective wavelengths & magnitude limits
(95% completeness for point sources)
u
3551Å
22.0
g
4686Å
22.2
r
6165Å
22.2
i
7481Å
21.3
z
8931Å
20.5
Relative photometric
calibration accuracy (RMS)

(Padmanabhan et al. 2008)
u
1.3%
g
0.8%
r
0.8%
i
0.7%
z
0.8%

Optical spectroscopy data statistics

All programs combined

Total spectra
4,851,200
Useful spectra
4,151,126
Galaxies
2,541,424
Quasars
680,843
Stars
928,859
Sky
394,231
Standards
88,788
Unknown
217,055

Stellar (SEGUE)

Effective area (deg2)
1,317
Plates
229
Total spectra
155,520
Unique objects
138,099

Exoplanets (MARVELS)

Targets
11,040

Extragalactic (BOSS/eBOSS)

Statistic Total Unique
Spectroscopic effective area (deg2) 9,376
Plates 3,008 2,913
Spectra 2,987,105 2,696,287
All Galaxies 1,608,987 1,493,503
    CMASS 933,387 863,761
    LOWZ 369,673 344,423
All Quasars 539,297 444,217
    Main 242,556 212,156
    Main, 2.15 ≤ z ≤ 3.5 175,518 150,592
Stars 335,844 303,518
    Standard stars 62,979 50,574
Sky 282,344 261,098
Unclassified spectra 229,418 201,549

IFU spectroscopy (MaNGA)

Total galaxies
2,812
Unique galaxies
2,744
Plate scale
7 deg2
IFUs per plate
17
Wavelength
3600-10,000 Å

Infrared (APOGEE) spectroscopic data statistics

DR14 includes data for ~263,000 APOGEE targets. This includes 231,000 science targets, located in distinct types of survey fields:

~13,000 stars
in Bulge fields
~129,600 stars
in Halo and Halo Stream fields
~76,000 stars
in Disk fields
~3,200 stars
in Satellite Galaxies fields
~400 stars
in Kepler Objects of Interest (KOI) Program fields
~19,500 stars
in Star Cluster fields
~13,300 objects
in Ancillary Science fields
~1000 bright stars
observed with the NMSU 1m telescope + APOGEE, including bright standards

Exact counts are given in the table below.

Statistic Total Unique
Pointings 780
Plates 4,012 1,363
All stars 1,054,381 263,444
    with NMSU 1-m 1,438 1,018
Commissioning stars 27,387 12,914
Survey stars 872,844 184,148
    with S/N > 100 144,309
    with ≥ 3 visits 143,154
    with ≥ 12 visits 6,200
    Stellar parameter standards 10,006 1,300
    Radial velocity standards 288 15
    Telluric line standards 128,974 23,611
    Ancillary science program objects 37,369 12,641
    Kepler target stars 34,789 17,218