ESASky Legacy TAP: ESA Legacy Missions

ESASky legacy is a TAP (Table Access Protocol) service to provide the community access to complete, self-standing catalogues and data collections from ESA astronomy legacy missions, ensuring their long-term preservation. This service, which is an IVOA standard for most modern science archives, is an entry point to data products and their successors that can be exposed by ESASky.

The ESA Legacy Missions available in the ESASky legacy TAP are:

• Hipparcos
• Cos-B
• CoRoT

Legacy archive (HIPPARCOS):

The Hipparcos Catalogue (118,218 stars with 1 milliarcsec level astrometry) and the Tycho Catalogue (more than one million stars with 20-30 milliarcsec astrometry and two-colour photometry) were completed in August 1996 and its data products were released in June 1997. Further improved catalogues were made available to the science community later. This Galaxy charter mission has produced four major catalogues referred to as the Hipparcos-1 Catalogue, the Tycho-1 Catalogue, the Hipparcos-2 Catalogue, and the Tycho-2 Catalogue.

These are the 42 Hipparcos data products (catalogues and annexes) currently available via the ESASky legacy TAP query as a self-standing catalogue collection, providing a single unified method of accessing all Hipparcos/Tycho data products and their successors.​​​​​​ You can access them using the Topcat tool, selecting the option "Table Access Protocol (TAP) Query" in the VO menu, and introducing the TAP url in the "Select Service" pane.

The summary of the 42 data products (or 59 tables) is shown in Table 1. Hipparcos-1 data products are complete except for identification charts and light-curve figures which can be found in the file Hip1-CDROMs-Volume17.zip in the HIPPARCOS_PUBLIC_DATA area on the ftp.cosmos.esa.int ftp server. Tycho-1 has been completed with the Epoch Photometry Annex B, and Hipparcos-2 and Tycho-2 with Intermediate Astrometry data products. The latter is considered an extension, as these data had never been published before. The Tycho Slit Response Functions (SRFs) that have been used in the Tycho-2 data processing can be found here and are described here.

Source:

Most tables have been obtained from the CDS/VizieR TAP service, where column labels and descriptions underwent curation by CDS/VizieR. The tables in boldface were downloaded from the VizieR ftp instead of TAP service. The data models for hipparcos1 tables #3-#6 were also obtained from the VizieR ftp (so they include CDS metadata curation), including as metadata descriptions both explanations and corresponding notes. For 14 tables, we constructed the corresponding data model from the original documentation, using the original Hipparcos column label naming convention and including as metadata descriptions the original Hipparcos explanations. 

Since the Tycho-1 Epoch Photometry - Annex B data hosted at CDS/Vizier was severely corrupted, two tables in data product #32 marked with an asterisk) were recovered from original CD-ROMs kindly provided by Claus Fabricius, member of the Tycho consortium. Although still presenting a partial loss of the original data, fewer data records are affected by corruption. 

Data products #19, #21, #22, #23, #29, #30, #31 and #36 were tables originally stacked together in rows mixing header and data records. For the sake of database ingestion, these data products have been split in their basic table structures, and the legacy_astro TAP serves them individually. Unique keys allow connecting the records back together.

Hipparcos-2 data products #25-#29 are served in two versions: a CDS/VizieR version (namespace hipparcos2_cds) and a Springer book DVD version (namespace hipparcos2_dvd). Hipparcos-2 intermediate astrometry is only available on the DVD and it is important that these intermediate data are only used together with the astrometric reference parameters coming from the main tables from the same DVD. The raw contents of the DVD can be found in the file Hip2-DVD-Book.zip in the HIPPARCOS_PUBLIC_DATA area on the ftp.cosmos.esa.int ftp server.

Metadata:

• Sky coordinates RAdeg, DEdeg are provided in ICRS system in units of degrees, with epoch J1991.25 (average observing time for the Hipparcos mission), except for the Tycho-2 Intermediate Astrometry (J1992.0) and the Double Star Catalogue and Supplement and the Two-colour Photometry for Components of Hipparcos Doubles Catalogue, at observation epoch J2000.0.

• Currently, our Legacy Archive TAP server does not preserve the data precision for trailing zeroes. To retrieve the table precision information, please refer to the original table data model section and table number in Hipparcos Vol 1: Introduction and Guide to the Data, provided in column #8

• Question marks in the table descriptions are equivalent to dagger in the table data model shown in the documentation, meaning blank for undefined values.

• Asterisk at the beginning of the column description and numbers in brackets at the end of descriptions refer to Notes in the Hipparcos Vol 1: Introduction and Guide to the Data

• The original hipparcos1.hipoint and hipparcos1.hipjtran records have several occurrences of type overflow that have been replaced by "null" values.

• For 6 Tycho tables, a Tycho identifier (ID) was created as an aggregate of the TYC numbers. It is constructed from the GSC region number (TYC1)[1,9537], the running number within the region (TYC2)[1,12119], and a component identifier (TYC3)[1,4], separated by a hyphen between them, e.g. TYC 1-13-1.

Legacy archive (Cos-B): 

Legacy archive (CoRoT): 

CoRoT(Convection, Rotation and planetary Transits) is the first space mission dedicated to exoplanetary research and designed for this purpose. The spacecraft was equipped with a 27 cm-diameter afocal telescope and a 4-CCD wide-field camera, was built around the PROTEUS spacecraft bus, and operated in a low-Earth orbit (LEO) of ~900 km (polar). Launched in December 2006 the mission had a nominal lifetime of 2.5 years. The scientific mission was officially ended the 20th of June 2013 and the satellite was de-orbited on 17 June 2014. During its observation phase, CoRoT continuously observed star fields in the Milky Way for periods of up to 6 months, recording the photometric light curve of about 150 distinct bright stars (with a visible magnitude between 5.8 and 8) using the bright stars channel (also known as the seismology channel) and more than 160 000 faint stars (with a visible magnitude between 10.5 and 16) using the faint stars channel (also known as the exoplanet channel. The project was led by CNES, with contributions from ESA, Austria, Belgium, Germany, Spain and Brazil.

From a polar inertial circular orbit (90-degree inclination) at an altitude of 896 km, the CoRoT programme of observations was based on a yearly cycle of 4 runs. During the summer period from October to March, the telescope was pointed towards the anticentre of the Milky Way and during the winter period from April to September, in the opposite direction. Two observation runs (alternately 20 and 150 days) were achieved during each summer and winter period in general. Twice a year, when the Sun got closer to the orbit plane and was about to blind the telescope, the spacecraft performed a reversal attitude manoeuvre.

Some of the features of the 26 CoRoT fields are extracted from 2018A&A...619A..97D

CoRoT produced nearly 6 years of data that are accessible online. The "CoRoT Legacy Book" describes these data and their correction methods, the most recent highlights up to now, and the new space projects that inherit from CoRoT. The different scientific products levels were made available in various science archives.

The ESA Legacy TAP includes the last version (N2-4.4) of the Bright and Faint star catalogues produced by CoRoT. The provenance of these tables is the CDS/Vizier TAP.

These catalogues are complemented via DataLink with a download service of science-ready data products such as light curves (variations in star brightness over time) and full images, with their respective previews, as well as windescriptors. A fullimage is the image of the full CDD recorded at the beginning of the run during 3 orbits with no SAA crossing. In the beginning of each run, the flight software needs to be reconfigured in order to put in place the photometric apertures so as to optimize the signal-to-noise ratio of the measured light curves. The CoRoT EXOWIN software was dedicated to work with a trio of full frame images, from where the stars would be identified and a basket of around 6,000 stars per CCD would be assigned to a photometric aperture in the exostar channel. Windescriptors describe the windows and the masks defined to observe the targets.