AAVSO Photometric All-Sky Survey (APASS), underway since 2010,
covers the entire sky from 7.5 < V < 16.5 magnitude, and in the BVugrizY
bandpasses. A northern and a southern site are used, each with twin ASA
20cm astrographs and Apogee Aspen CG16m cameras, covering 2.9x2.9 square
degrees with 2.6arcsec pixels. Landolt and SDSS standards are used for
all-sky solutions, with typical 0.02mag calibration errors on the bright
end.
Data Release 10 is a complete reprocessing of all 500K images taken with
the system, including hundreds of nights not part of DR9. Sextractor is
used for star finding and centroiding; DAOPHOT is used for aperture
photometry; the astrometry.net plate-solving library is used for basic
astrometry, supplanted with more precise WCS that utilizes knowledge of the
optical train distortions. With these changes, DR10 includes many more
stars than prior releases.
More information is available at http://www.aavso.org/apass.
This brief tutorial shows you how to quickly add proper motions and
photometry from Gaia to (almost) any object list using the Virtual
Observatory. The VO protocol most suited to this kind of this is TAP
("table access protocol") and lets you transfer data and queries to
database servers. In the example, we will be using TOPCAT as a client.
There is no lock-in to it: There are libraries and other tools
allowing an integration of TAP operations into arbitrary workflows –
that's what standards are about. Tutorial supplements apply the
techniques to Simbad, show how to use TAP from Python, and introduce
UCDs.
The VO client Aladin offers powerful facilities of creating an
astrometrical calibration to images lacking WCS (World Coordinate
System) information. This tutorial shows how to go about doing this
for an image of the Ring Nebula in Lyr.
This tutorial uses SPLAT-VO to search the VO registry for spectra of
galaxies and quasars. From the obtained spectra, the Hydrogen Lyman
Alpha line will be used to compute redshift and velocity
Within this intermediate use case you learn about supernovae (see
also the tutorial “Distance to the Crab Nebula“,
ivo://edu.euro-vo.org/tutorials/08_m1_distance) and determine the
celestial coordinates of a just discovered candidate supernova on an
provided image without astrometric calibration. This use case provides
a glimpse of an activity that is representative of the practical tasks
that astronomers have to perform when they analyze data.
Introduction to Simulation Databases - Density Fields and Dark Matter
Halos
Date:
23 Mar 2022 13:13:13
Publisher:
The GAVO DC team
Description:
This tutorial was created for a physics teacher workshop (~ high
school level). It shows how to extract density fields and information
on dark matter halos from the CosmoSim database using SQL queries. It
is optimized for brevity.
Introduction to Simulation Databases Using CosmoSim
Date:
23 Mar 2022 13:13:08
Publisher:
The GAVO DC team
Description:
This tutorial shows how to do first SQL-queries on cosmological
databases, including retrieving mass functions, extracting merger
trees or particles of a specific dark matter halo.
Outlier Analysis in Low-Resolution Spectra: DFBS and Beyond
Date:
11 Apr 2023 13:12:10
Publisher:
The GAVO DC team
Description:
Low-resolution spectra like those resulting from objective prism
observations or the RP/BP instrument on board of the Gaia astrometry
satellite enable a wealth of interesting science. This use case
investigates one use leading up to combining many VO resources: The
identification of misclassified objects from reference databases.
This tutorial introduces a few techniques for working with image
services in the Virtual Observatory (VO) in general, using services
containing plate scans as examples. It will discuss both exploratory,
interactive use, and scripting using pyVO.