Pre-release of Gaia DR4 astrometric parameters for a star to be occulted by uranus

 

2024-11-04 Pre-release of Gaia DR4 astrometric parameters for a star to be occulted by Uranus

On 12 November 2024 the star Gaia DR3 56716009513720320 will be occulted by the Solar System planet Uranus, which offers a rare opportunity to study the ring system and atmosphere of the planet. To allow for the best-possible planning for the ground-based occultation observing campaigns, we make the preliminary Gaia Data Release 4 (Gaia DR4) single-star astrometric solution parameters for this star public:

 

Object to be observed Parameter name Star occulted by Uranus
Date of occulation event   12 November 2024
Gaia DR4 source ID   56716009513720320
Epoch / Reference frame   2017.5 / ICRF
Right Ascension (RA) [degrees] ra 52.79021223955437
RA uncertainty [mas] ra_error 0.0498831
Declination (DEC) [degrees] dec 18.774062713584225
DEC uncertainty [mas] dec_error 0.040730022
Proper Motion in Right Ascension
(PM in RA) [mas/yr]

pmra

 1.8737964684191688
Uncertainty of
PM in RA [mas/yr]		 pmra_error 0.033426166
Proper Motion in Declination
(PM in DEC) [mas/yr]		 pmdec 17.616657694619814
Uncertainty of
PM in DEC [mas/yr]		 pmdec_error 0.023165625
Parallax [mas] parallax 1.8753995551910554
Parallax uncertainty [mas] parallax_error 0.057721965
Parameters solved for in the model astrometric_params_solved 95
Astrometrically estimated pseudocolour [1/micrometre] pseudocolour 1.54409
Uncertainty of pseudocolour [1/micrometre] pseudocolour_error 0.00806472

Table: Gaia DR4 single-star solution parameters of the star that will be occulted by Uranus. The parameter name can be used to look up the detailed description in the Gaia DR3 online documentation. Credit: ESA/Gaia/DPAC, please follow the acknowledgment guidelines as given here and please also cite the Gaia mission paper.

 

The predicted occultation path is published by the Lucky Star Project on this website: https://lesia.obspm.fr/lucky-star/occ.php?p=131499

 

Occultation map for the occultation by Uranus on 12 November 2024, currently obtained using Gaia DR3 data. More details from source: https://lesia.obspm.fr/lucky-star/occ.php?p=131499.

 

In 2016, before Gaia's first data release (Gaia DR1), a similar effort was done for the occultation observation of Pluto, a story that can be found here. A pre-release of Gaia DR2 data was made in 2017 in support of occultation events of Triton and Chariklo, see the details here. The Gaia mission also helped with the occultation campaigns for the Kuiper Belt Object observed by the NASA New Horizons mission (more details here). More details on how Gaia helps stellar occultation in general can be found here and from the published stories "Astronomers spy Europa blocking distant star - thanks to Gaia" and "Shadow hunters capture Didymos asteroid eclipsing stars".

The Gaia Data Processing and Analysis Consortium is currently processing the Gaia data and Gaia Data Release 4 is expected not before mid 2026.