The long-time awaited Gaia Data Release 2 is finally available in the Gaia Science Archive from April 25, 2018. Users can also query the main catalogue through ESASky. Both services feature new or improved functionalities to make the exploration and retrieval of the data easier and more efficient.
This data release provides positions, parallaxes and proper motions for more than 1.3 billion stars between G-magnitudes 3 and 21; for most of these sources, also the GBP and GRP magnitudes are given. On top of this, it also provides median radial velocities for more than 7.2 stars with median G-magnitudes between 4 and 13 and effective temperatures between 3550 and 6900 K. Parallax uncertainties span between 0.04 for G < 17 mag and 0.7 mas at G=20. Proper motion uncertainties range from less than 0.06 mas/yr for G<15 mag to 1.2 mas/yr for G=20 mag. The radial velocity precision ranges from 200-300 m/s at the bright end to 1.2 and 2.5 km/s at the faint end for stars of effective temperatures of 4750 and 6500 K, respectively.
For a complete description of this data release, refer to the Gaia contents and documentation pages.

Image: ESA/Gaia DPAC

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The Gaia Science Archive keeps for Data Release 2 a balance between old and new features. The main product is still a big catalogue (gaia_source), which is accessible using ADQL queries via the existing TAP interface and different layers on top for improved usability (Archive GUI, command line scripts, third party tools such as Topcat, ...). Access to the previous DR1 is preserved, as well as cross-matches between DR2 and DR1 and with many of the main astronomical catalogues (AllWISE, APASS DR9, GSC2.3, Pan-STARRS, PPMXL, RAVE DR5, SDSS DR9, 2MASS, Tycho-2, etc.). Copies of most of the external catalogues are also provided to allow easy metadata combination.
Significant work has been invested to prepare the system for the upcoming challenges posed by future data releases. The much larger associated data volumes (by factors up to a thousand) require the development of novel strategies. Hardware architecture based on parallel databases will allow the publication of future Gaia data releases until the final one (foreseen for around 2022). Two new services have been introduced, the Virtual Observatory DataLink protocol, providing an index of the additional resources available for each source beyond the TAP, and a Massive Data server, which distributes the light curves for the circa 550,000 identified variable stars. An introductory tutorial is available in the Help pages.
Other interesting features include routines for rigorous astrometric epoch propagation (including positions), statistical plots of the main Gaia catalogue, the novel use of arrays for a selected subset of variability tables and the continuity of the popular bulk download server.
One key objective for DR2 is to collect astronomers' feedback on usability. Please, report to the Helpdesk your findings, specially if related to the DataLink and Massive Data new services.

Members of the Gaia Archive development team: J. Salgado, J. González, R. Gutiérrez, J.C. Segovia, J. Durán, E. Racero, P. de Teodoro
Image: ESA/ESDC (R. Gutiérrez)

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Just in time for Gaia DR2! The newest version of ESASky not only provides access to the main Gaia DR2 catalogue, but it also offers enhanced data exploration functionalities.
In particular, for astrometric catalogues, proper motions are now displayed as vectors. Moreover, to make the displayed information more easily distinguishable from the background sky, it is now possible to customise the shape, size and colour of the catalogue source symbols, as well as the colours of the footprints from imaging and spectroscopic observations and the size of the proper motion arrows. Furthermore, the table tabs in the data panel now include a question mark symbol that opens a pop-up window with information on the data and the way they have been integrated in ESASky.
In addition to Gaia DR2, the new datasets provided with this version are the AllWISE and 2MASS catalogues and a number of new radio all-sky maps (HiPS). Last but not least, the publications functionality has been improved for better usability.
For more information on this release, go to the ESASky documentation pages.

Members of the ESASky development team: F. Giordano, H. Norman, R. Vallés, E. Racero, D. Baines, M. López Caniego, B. López Martí, P. de Teodoro, B. Merín, J. Salgado
Image: ESA/ESDC

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The joint ESA/NASA Ulysses mission conducted the first out-of-ecliptic study of the heliosphere, being the first mission to study the Sun at all latitudes. Operations ceased in June 2009, but its data are still very valuable for the Heliophysics community.
The Ulysses Final Archive, whose latest version (1.1.0) was released on March 21, has been developed by the ESDC in collaboration with the Ulysses Data System Team with the goal of long-time preserving the unique data from this mission. The web interface provides state-of-the-art tools to explore the archive data contents, pre-generated plots, extended documentation on the instrument and data, and links to other software resources.
In the last month, the usage of the archive has increased by a factor of ten, from an average of 30 users per month to more than 300, a proof of the importance of legacy data for the scientific community.

Members of the UFA development team: B. Martínez, A. Masson, H. Pérez, J. Cook, M. Fernández
Image: ESA/ESDC

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The ESA SPICE Service (ESS) and the Navigation and Ancillary Information Facility (NAIF) will conduct a SPICE observation geometry training class on June 19-22, 2018 in Madrid, Spain.
SPICE is an information system the purpose of which is to provide scientists the observation geometry needed to plan scientific observations and to analyse the data returned from those observations. SPICE data are used by all the projects to generate the geometry parameters for the Planetary Science Archive (PSA) and is also a Bundle/Dataset that is archived. For more information, refer to ESA’s SPICE documentation pages.
The class is free and open to all professionals and students involved in Solar System exploration. Further information about the class and the class registration form are found at the training class website. Registration is due by May 30, 2018.
Image: ESA/ESS

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