COSMOS IoW 2021 - Gaia

IoW 2021 - Gaia

Gaia Image of the Week 2021

2021-12-23 Signal-to-Noise Ratio estimate for Gaia DR3 BP/RP mean spectra

23 December 2021 The upcoming 3rd Gaia Data Release (Gaia DR3) will introduce for the first time BP/RP mean spectra in the wide range of Gaia data products. The exact number of sources for which BP/RP mean spectra will be published is still undefined but it is expected to be of the order of 100 million. The vast majority of these sources will be brighter than... read more

2021-12-22 Stellar occulation of the Neptunian system

22 December 2021 On October 7, 2021, The Lucky Star team at Observatoire de Paris (France) led and organised the largest occultation and imaging campaign by the Neptunian system ever undertaken since the Voyager flyby in 1989. This occultation event was observable across the Americas (North, Central, and South) as well as in Hawaii, and the campaign involved all... read more

2021-12-01 Observation of a long-predicted new type of binary star

1 December 2021 By combining data from different surveys and organising follow-up observations of selected candidates, a team of researchers has observed a new type of binary star that was long predicted to exist. The discovery finally confirms how such a rare type of star in the universe forms and evolves. The results have been described in Monthly Notices of... read more

2021-09-24 astrometric microlensing effect in the Gaia16aye event

24 September 2021 Gaia16aye was a binary microlensing event detected by Gaia in 2016 as one of the first transients of that kind reported by Gaia Photometric Science Alerts (Hodgkin et al. 2021). The event has been followed-up from the ground by a network of telescopes over the period of two years (see our image of the week story of october 2016 and the story... read more

2021-09-22 The discovery of a gigantic cavity in space

22 September 2021 Looking up from Earth, the stars we see are shown on the canvas of the sky in two dimensions. Though stars or constellations may appear to be close to one another, appearances can be deceiving. With the parallax measurements from Gaia a third dimension is available. Knowing the parallax of a star allows to deduce its distance, which truly allows... read more

2021-09-16 An alternative Gaia sky chart

16 September 2021 Everyone working in the DPAC or using the Gaia results knows how much mathematic modelling and computer science take place behind the stage to transform the dull raw material delivered by the telescopes into an incredible epoch-making catalogue. In this story one shows that with only simple arithmetic, repeated additions (admittedly nearly 180... read more

2021-08-25 Gaia photometric science alerts and gravitational wave triggers

25 August 2021 Motivated by the recent developments in multi-messenger astronomy, and in particular the detection of an electro-magnetic counterpart to the gravitational wave (GW) event GW170817, and by the non-detections of subsequent GW events involving at least one neutron star, a contribution from Gaia to this emerging field has been discussed. read more

2021-07-09 GSP-Spec at work

9 July 2021 Gaia RVS stellar spectra, at a resolution of ~11500, contain a wealth of information about Milky Way stars. This animation shows several Gaia RVS stellar spectra, presenting the stellar flux (black dots) in the wavelength interval between 846 and 870 nm (in vacuum). The flux is normalized to the continuum, showing variations (spectral lines) due... read more

2021-06-23 Interview with Coordination Unit 3

23 June 2021 The Gaia data releases contain a wealth of astrophysical data on about 1.8 billion stars in our Milky Way and beyond. The creation of these data releases is in the hands of the Gaia Data Processing and Analysis Consortium, Gaia DPAC, which has itself organised in 9 Coordination Units with help from 6 Data Processing Centres. Each coordination... read more

2021-04-27 HIP 70674 orbital solution resulting from Gaia DR3 processing

27 April 2021 In 2015, after one year of data acquisition by Gaia, we reported the case of HIP 70674, a well-known double lined spectroscopic binary (SB2), with visual magnitude V=7.99. The aim was to demonstrate the capability of the Coordination Unit 6 (CU6) Single Transit Analysis (STA) pipeline to measure radial velocities from double lined spectra as... read more

2021-03-30 First Transiting Exoplanet by Gaia

30 March 2021 Gaia is sampling more than a billion Milky-Way stars at a mean rate of 15 times per year. The Gaia scanning law was optimised for obtaining precise astrometry and is therefore not optimal for detecting planets that transit periodically the disk of their host stars. Nevertheless, this type of events can in principle be seen in the Gaia data. In... read more

2021-03-26 Apophis' Yarkovsky acceleration improved through stellar occultation

26 March 2021 Well before Gaia published its first astrometric releases, its promising impact for observing stellar occultations by a variety of bodies of the Solar System was thrilling. Those expectations were fully met, and a recent breakthrough shows that reality even surpassed our prospects. On 7 March 2021, and for the first time ever, the occultation of... read more

2021-02-26 Matching observations to sources for Gaia DR4

26 February 2021 While the scientific community is analysing the first batch of the Gaia DR3 data, part of the Data Processing and Analysis Consortium (DPAC) is already engaged in the production of Data Release 4. The Intermediate Data Update (IDU) pipeline and the Data Processing Centre of Barcelona delivered the results of the first cross-match run in... read more