Digitized First Byurakan Survey (DFBS) Spectra Query Service
Short Name:
DFBS SSAP
Date:
27 Dec 2024 08:31:13
Publisher:
The GAVO DC team
Description:
The First Byurakan Survey (FBS) is the largest and the first systematic
objective prism survey of the extragalactic sky. It covers 17,000 sq.deg.
in the Northern sky together with a high galactic latitudes region in the
Southern sky. The FBS has been carried out by B.E. Markarian, V.A.
Lipovetski and J.A. Stepanian in 1965-1980 with the Byurakan Observatory
102/132/213 cm (40"/52"/84") Schmidt telescope using 1.5 deg. prism. Each
FBS plate contains low-dispersion spectra of some 15,000-20,000 objects;
the whole survey consists of about 20,000,000 objects.
Discovery of Brown Dwarfs mining the 2MASS and SDSS databases
Date:
27 Dec 2024 08:31:05
Publisher:
The GAVO DC team
Description:
Brown dwarfs are objects occupying the gap between the least massive
stars and the most massive planets. They are intrinsically faint
objects so their detection is not straighforward and, in fact, was
almost impossible until the advent of global surveys at deep optical
and near-infrared bands like SDSS, 2MASS or DENIS among others. We
propose here to mine the 2MASS-PSC and SDSS-DR9 databases to identify
T-type brown dwarfs through an appropriate combination of colours in
the optical and the infra-red, an approach that perfectly fits into
the Virtual Observatory.
Within this use case for high school students and adanced amateurs
you measure the linear distance of the Andromeda Galaxy following the
steps of the astronomers who first measured it, climbing an important
step of the so-called cosmic distance ladder. The use case requires
the identification of variable stars of the Cepheid class and the
determination of the relation between their period and their intrinsic
luminosity.
Within this use case you learn about supernovae, exploding or
exploded stars. In particular you will use information on the Crab
Nebula (the 1054 aD supernova registered by Chinese astronomers) to
derive its distance: an example of how some very important information
may be gained from very simple arguments and geometry.
The EPN-TAP 2.0 version of the complete asteroid data from the Minor
Planet Center (MPC), updated once per month. The MPC operates at the
Smithsonian Astrophysical Observatory under the auspices of Division
III of the International Astronomical Union (IAU).
The MPC Orbit database contains orbital elements of minor planets that
have been published in the Minor Planet Circulars, the Minor Planet
Orbit Supplement and the Minor Planet Electronic Circulars.
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
As stars in open star clusters are formed from the same matter at the
same time and have only a small velocity dispersion, it is relatively
easy to identify them from the background stars. In this tutorial, we
will identify the members of the Pleiades kinematically and get an
idea of our success by examining a color-magnitude diagram using
TOPCAT, Aladin, and a few VO services.
This tutorial uses data from Gaia DR2 to lead you through some of the
capabilities of TOPCAT and STILTS. Use cases covered include a studies
of the globular cluster M4 in proper motion space and the open cluster
Hyades in the full phase space, matches between Gaia and HST data, and
the creation of Hertzsprung-Russell diagrams.
![To the extent possible under law, the publisher has waived all copyright and related or neighboring rights to GAVO's ADQL course. For details, see the `Creative Commons CC0 1.0 Public Domain dedication <http://creativecommons.org/publicdomain/zero/1.0/>`_. Of course, you should still give proper credit when using this data as required by good scientific practice. .. image:: /static/img/cc0.png :alt: [CC0]](/registry-search/?f%5Bpublisher_facet_trim%5D%5B%5D=The+GAVO+DC+team&f%5Brights_facet%5D%5B%5D=To+the+extent+possible+under+law%2C+the+publisher+has+waived+all+copyright+and+related+or+neighboring+rights+to+GAVO%27s+ADQL+course.++For+details%2C+see+the+%60Creative+Commons+CC0+1.0+Public+Domain+dedication+%3Chttp%3A%2F%2Fcreativecommons.org%2Fpublicdomain%2Fzero%2F1.0%2F%3E%60_.++Of+course%2C+you+should+still+give+proper+credit+when+using+this+data+as+required+by+good+scientific+practice.%0A%0A..+image%3A%3A+%2Fstatic%2Fimg%2Fcc0.png%0A+++%3Aalt%3A+%5BCC0%5D%0A%0A&f%5BvalidationLevel_facet%5D%5B%5D=2){kind=link}