Differences between USNO-B and PPMXL in positions and proper
motions, on
an all-sky one-degree grid. At each gridpoint we give the
differences X(PPMXL)- X(USNO-B1.0) averaged over all stars in
a sqrt(2)/2-degrees environment around the gridpoint given. The
corrections given here should bring USNO-B based astrometry to the ICRS.
The Online Digitized Sky Surveys (DSS1 & 2) server at the ESO/ST-ECF Archive provides access to the CD-ROM set produced by the Space Telescope Science Institute through its Guide Star Survey group. The images of these surveys are based on photographic data obtained using the Oschin Schmidt Telescope on Palomar Mountain and the UK Schmidt Telescope. The plates were processed into the present compressed digital form with the permission of these institutions. The photographic plates were scanned to a pixel scale of about 1.7 arcseconds per pixel for the POSS, SERC, and Palomar Quick-V surveys, and to about 1.0 arcseconds per pixel for the POSS-II surveys. Images of any part of the sky may be extracted from the DSS, in either FITS or GIF format.
Estimated distances to 1.33 billion stars in Gaia DR2
Short Name:
gdr2dist scs
Date:
27 Dec 2024 08:31:05
Publisher:
The GAVO DC team
Description:
This catalogue provides distances estimates (and uncertainties therein)
for 1.33 billion stars over the whole sky brighter than about G=20.7.
These have been estimated using the parallaxes (and their uncertainties)
from Gaia DR2. A Bayesian procedure was used involving a prior
with a single parameter L(l,b), which varies smoothly with Galactic
longitude and latitude according to a Galaxy model. The posterior is
summarized with a point estimate (usually the mode) and a confidence
interval (usually the 68% highest density interval). The estimation
procedure is described in detail in the `accompanying paper`_,
which also analyses the catalogue content.
.. _accompanying paper: http://www.mpia.de/homes/calj/gdr2_distances.html
The Faint Object Camera (FOC) was one of the 4 original axial instruments on the Hubble Space Telescope (HST). FOC is used to make high-resolution observations of faint sources at UV and visible wavel
The Faint Object Spectrograph (FOS) was one of the 4 original axial instruments aboard the Hubble Space Telescope (HST). The FOS was designed to make spectroscopic observations of astrophysical sources from the near ultraviolet to the near infrared (1150 - 8000 Angstroms). The instrument was removed from HST during the Second Servicing Mission in February 1997.