Friday, September 30, 2016

A new all sky star catalog of our very own favorite galaxy is being released 2016.
Launched 1000 days ago, Gaia started its scientific work in July 2014. This first release is based on data collected during its first 14 months of scanning the sky, up to September 2015.

"Today's release gives us a first impression of the extraordinary data that awaits us and how that will revolutionize our understanding of how stars are distributed and move across our galaxy."

"The beautiful map we are publishing today shows the density of stars measured by Gaia across the entire sky, and confirms that it collected superb data during its first year of operations” 
says Timo Prusti, Gaia project scientist at ESA.

The September 2016 release

Will have information about positions (α, δ) and G  magnitudes for all stars with acceptable formal standard errors on positions. Positions and individual uncertainties are computed using a generic prior and bayes' rule detailed in the "Gaia astrometry for stars with too few observations. A Bayesian approach"  For this release approximately 90% of the sky will be covered. At the beginning of the routine phase, a special scanning mode repeatedly covering the ecliptic poles on every spin was executed for calibration purposes. Photometric data of RR lyrae and Cepheid Variable Stars including these high-cadence measurements will be released. The five parameter astrometric solution  positions, parallaxes, and proper motions for stars in common between the Tycho 2 Catalog and Gaia will be released. The catalog is based on the Tycho-Gaia Astrometric Solution. (Image of the Week with short TGAS descriptionpaper with a more detailed description; paper describing theory and backgroundpaper describing quasar extension)

Future releases may Include: 

Five parameter astrometric solution of objects with single star behavior will be released under the assumption that at least 90% of the sky can be covered. Integrated BP/RP photometry, with appropriate standard errors for sources where basic astrophysical parameter estimation has been verified. Mean radial velocities for objects showing no radial velocity variation and for which an adequate synthetic template could be selected, under the assumption that this can be done for 90% of the bright stars on the sky.

Orbital solutions, together with the system radial velocity and five parameter astrometric solutions, for binary having periods between 2 months and 75% of the observing time will be released. Object classification and astrophysical parameters, together with BP/RP spectra and/or RVS spectra they are based on, will be released for spectroscopically and photometrically well behaved objects. Mean radial velocities will be released for those stars not showing variability and with available atmospheric parameter estimates.

Variable star classification will be released together with the epoch photometry used for the stars. Solar system results will be released with preliminary orbital solutions and individual epoch observations. Non single star catalogs will be released.Full astrometris, photometric and radial velocity catalogs will alse be released. All available variable star and non single star solutions. Source classification plus multiple asrtophysical parameters for stars, unresolved binaries, galaxues, and quasars. Some parameters may not be available for fainter stars.

Also to be released!

An Exo Planet List
All Epoch and transit data for these planets.
All ground based observations made for data processing. 

We look forward to the full data releases coming and upcoming discoveries.

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