Image of the Week

Asteroids in Gaia

 

 

Figure 1: Gaia's first survey of asteroids (Image credit: ESA/Gaia/DPAC, acknowledgement: P. Tanga)

 

Apart from providing a huge catalogue of almost 1.7 billion stars, Gaia now also serves the solar system community with its first survey of asteroids, released on 25 April with the Gaia second data release. In this image of the week a short history of Gaia's asteroid survey is given.

 

Before launch in 2013, an illustration was published on Gaia's expected advantage to probe the asteroid blind spot (Illustration on 22/10/2013: Gaia will probe the asteroid blind spot). Gaia operates from the second Lagrange point L2 of the Sun-Earth system, a point that moves along with Earth while Earth orbits the Sun. From this location, Gaia is capable to discover small bodies orbiting the Sun inside the Earth's orbit. From Earth, these objects are mostly unobservable. An artist impression animation shows what Gaia can observe with respect to what can be observed from Earth.

During commissioning (a phase during which all operations to prepare for the routine operational phase are performed), an article was published that gives "Predictions for the Detection of Earth and Mars Trojan Asteroids by the Gaia satellite" (Story on 06/01/2014: Asteroid detection by Gaia). Several test observations were obtained during this phase, also revealing some asteroids moving through the Gaia focal plane (Story on 03/07/2014: IoW: Asteroids at the photo finish - Blog: Asteroids at the photo finish)

Once Gaia started it's routine operations, time came to test the processing pipeline for asteroid detection. Eight months of Gaia data and a sample of 50,000 asteroids were used to test the detection efficiency of the software in the Gaia processing pipeline. More information on this test can be found in this image of the week story of 31/07/2015: Asteroids all around (or the accompanying story: Gaia's asteroid detections).

With Gaia's first data release, the precise astrometry of the stars started to make observation of asteroids through stellar occultation methods more easy. Only a few days after the release of Gaia DR1, the predicted shadow path of the stellar occultation by minor planet (671) Carnegia was updated using the more precise position of the to-be-occulted star from Gaia DR1. This allowed for an amateur astronomer in New Zealand to successfully observe this occultation (21/10/2016: First post-Gaia asteroid occultation success: a feedback from amateur astronomy).

While the Gaia Data Processing and Analysis Consortium was working towards the second data release, a short story on how Gaia reveals the composition of asteroids was published, discussing what the data from cycle 1 of the processing revealed and to show the potential of Gaia with respect to this type of analysis (24/04/2017: Gaia reveals the composition of asteroids).

To allow for quick follow-up of potentially newly discovered solar system objects, a follow-up network for solar system objects was started listing all these potential asteroid discoveries made by Gaia waiting for a confirmation by follow-up observations (24/01/2017: Gaia follow up network for solar system objects). To help the community plan for observations, the Gaia-GOSA service offers a forum to discuss and plan observing campaigns and gives an overview of interesting asteroids in need for follow-up (24/11/2017: Gaia-GOSA service).

More stories discussing Gaia's road to observing Solar System objects were published in 2017: Gaia turns its eyes to asteroid hunting and Asteroid Gaia-606 on 26 October 2016. To show the selection of asteroids detected by Gaia that would be published in the second data release, a video was created which can be found here: Selected asteroids detected by Gaia between August 2014 and May 2016.

Asteroids as detected by Gaia between August 2014 and May 2016

 

The impact of again more precise positions of stars given by Gaia's data release 2 was illustrated with the pre-release of a few Gaia DR2 stars to allow for improving the predicted occultation path by asteroid Chariklo. More information on this stellar occultation and Gaia's impact can be found here: Chariklo stellar occultation follow-up.

The first survey of asteroids by Gaia was released on 25 April 2018 and is part of Gaia's second data release. This first survey is described in these stories: Gaia's first asteroid survey (see Figure 1), Solar System Objects in Gaia DR2, Gaia's view of more than 14,000 asteroids.

Visualisation of the Gaia DR2 asteroids

 

In the below figure, the orbits of this full set of 14,099 asteroids are given each with a very specific colour code: coloured by perihelion distance (on the left), coloured by eccentricity of the orbit (in the middle) or coloured by the albedo of the asteroid (on the right).

 

 

Figure 2a: Plot of the orbits of the asteroids in Gaia Data Release 2. Left image is coloured according to perihelion distance (the distance of the asteroid in its orbit where it is closest to the Sun). Center image is coloured following the eccentricity of the asteroids. Right image is coloured following the albedo of the asteroids. ESA/Gaia/DPAC, P. Tanga

Figure 2b: Zooms of the plot of the orbits as shown in Figure 1a. Left image is coloured according to perihelion distance. Center image is coloured following the eccentricity of the asteroids. Right image is coloured following the albedo of the asteroids. ESA/Gaia/DPAC, P. Tanga

 

More info on the asteroid data in Gaia Data Release 2 is given in the below video and can be found from the Gaia Data Release Documentation and Gaia DR2 papers describing the processing and the full data set.

Explanation of the asteroid data in Gaia Data Release 2

Credits: ESA/Gaia/DPAC, Coordination Unit 4 on Objects Processing, P. Tanga, F. Spoto, and co-authors of the paper "Gaia Data Release 2: Observations of Solar System objects"

[Published: 30/06/2018]

 

Image of the Week Archive

2018
19/11: Hypervelocity White Dwarfs in Gaia data
15/11: Hunting evolved carbon stars with Gaia RP spectra
13/11: Gaia catches the movement of the tiny galaxies surrounding the Milky Way
06/11: Secrets of the "wild duck" cluster revealed
12/10: 25 years since the initial GAIA proposal
09/10: 3rd Gaia DPAC Consortium Meeting
30/09: A new panoramic sky map of the Milky Way's Stellar Streams
25/09: Plausible home stars for interstellar object 'Oumuamua
11/09: Impressions from the IAU General Assembly
30/06: Asteroids in Gaia Data
14/06: Mapping and visualising Gaia DR2

25/04: In-depth stories on Gaia DR2

14/04: Gaia tops one trillion observations
16/03: Gaia DR2 Passbands
27/02: Triton observation campaign
11/02: Gaia Women In Science
29/01: Following-up on Gaia
2017
19/12: 4th launch anniversary
24/11: Gaia-GOSA service
27/10: German Gaia stamp in the making
19/10: Hertzsprung-russell diagram using Gaia DR1
05/10: Updated prediction to the Triton occultation campaign
04/10: 1:1 Gaia model arrives at ESAC
31/08: Close stellar encounters from the first Gaia data release
16/08: Preliminary view of the Gaia sky in colour
07/07: Chariklo stellar occultation follow-up
24/04: Gaia reveals the composition of asteroids
20/04: Extra-galactic observations with Gaia
10/04: How faint are the faintest Gaia stars?
24/03: Pulsating stars to study Galactic structures
09/02: Known exoplanetary transits in Gaia data
31/01: Successful second DPAC Consortium Meeting
2016
23/12: Interactive and statistical visualisation of Gaia DR1 with vaex
16/12: Standard uncertainties for the photometric data (in GDR1)
25/11: Signature of the rotation of the galactic bar uncovered
15/11: Successful first DR1 Workshop
27/10: Microlensing Follow-Up
21/10: Asteroid Occultation
16/09: First DR1 results
14/09: Pluto Stellar Occultation
15/06: Happy Birthday, DPAC!
10/06: 1000th run of the Initial Data Treatment system
04/05: Complementing Gaia observations of the densest sky regions
22/04: A window to Gaia - the focal plane
05/04: Hipparcos interactive data access tool
24/03: Gaia spots a sunspot
29/02: Gaia sees exploding stars next door
11/02: A new heart for the Gaia Object Generator
04/02: Searching for solar siblings with Gaia
28/01: Globular cluster colour-magnitude diagrams
21/01: Gaia resolving power estimated with Pluto and Charon
12/01: 100th First-Look Weekly Report
06/01: Gaia intersects a Perseid meteoroid
2015
18/12: Tales of two clusters retold by Gaia
11/11: Lunar transit temperature plots
06/11: Gaia's sensors scan a lunar transit
03/11: Celebrity comet spotted among Gaia's stars
09/10: The SB2 stars as seen by Gaia's RVS
02/10: The colour of Gaia's eyes
24/09: Estimating distances from parallaxes
18/09: Gaia orbit reconstruction
31/07: Asteroids all around
17/07: Gaia satellite and amateur astronomers spot one in a billion star
03/07: Counting stars with Gaia
01/07: Avionics Model test bench arrives at ESOC
28/05: Short period/faint magnitude Cepheids in the Large Magellanic Cloud
19/05: Visualising Gaia Photometric Science Alerts
09/04: Gaia honours Einstein by observing his cross
02/04: 1 April - First Look Scientists play practical joke
05/03: RR Lyrae stars in the Large Magellanic Cloud as seen by Gaia
26/02: First Gaia BP/RP deblended spectra
19/02: 13 months of GBOT Gaia observations
12/02: Added Value Interface Portal for Gaia
04/02: Gaia's potential for the discovery of circumbinary planets
26/01: DIBs in three hot stars as seen by Gaia's RVS
15/01: The Tycho-Gaia Astrometric Solution
06/01: Close encounters of the stellar kind
2014
12/12: Gaia detects microlensing event
05/12: Cat's Eye Nebula as seen by Gaia
01/12: BFOSC observation of Gaia at L2
24/11: Gaia spectra of six stars
13/11: Omega Centauri as seen by Gaia
02/10: RVS Data Processing
12/09: Gaia discovers first supernova
04/08: Gaia flag arrives at ESAC
29/07: Gaia handover
15/07: Eclipsing binaries
03/07: Asteroids at the "photo finish"
19/06: Calibration image III - Messier 51
05/06: First Gaia BP/RP and RVS spectra
02/06: Sky coverage of Gaia during commissioning
03/04: Gaia source detection
21/02: Sky-background false detections in the sky mapper
14/02: Gaia calibration images II
06/02: Gaia calibration image I
28/01: Gaia telescope light path
17/01: First star shines for Gaia
14/01: Radiation Campaign #4
06/01: Asteroid detection by Gaia
2013
17/12: Gaia in the gantry
12/12: The sky in G magnitude
05/12: Pre-launch release of spectrophotometric standard stars
28/11: From one to one billion pixels
21/11: The Hipparcos all-sky map
15/10: Gaia Sunshield Deployment Test
08/10: Initial Gaia Source List
17/09: CU1 Operations Workshop
11/09: Apsis
26/08: Gaia arrival in French Guiana
20/08: Gaia cartoons
11/07: Model Soyuz Fregat video
01/07: Acoustic Testing
21/06: SOVT
03/06: CU4 meeting #15
04/04: DPCC (CNES) 
26/03: Gaia artist impression 
11/02: Gaia payload testing  
04/01: Space flyby with Gaia-like data
2012
10/12: DPAC OR#2. Testing with Planck
05/11: Galaxy detection with Gaia
09/10: Plot of part of the GUMS-10 catalogue
23/07: "Gaia" meets at Gaia
29/06: The Sky as seen by Gaia
31/05: Panorama of BAM clean room
29/03: GREAT school results
12/03: Scanning-law movie
21/02: Astrometric microlensing and Gaia
03/02: BAM with PMTS
12/01: FPA with all the CCDs and WFSs
2011
14/12: Deployable sunshield
10/11: Earth Trojan search
21/10: First Soyuz liftoff from the French Guiana
20/09: Fast 2D image reconstruction algorithm
05/09: RVS OMA
10/08: 3D distribution of the Gaia catalogue
13/07: Dynamical Attitude Model
22/06: Gaia's view of open clusters
27/05: Accuracy of the stellar transverse velocity
13/05: Vibration test of BAM mirrors
18/04: L. Lindegren, Dr. Honoris Causa of the Observatory of Paris
19/01: Detectability of stars close to Jupiter
05/01: Delivery of the WFS flight models
2010
21/12: The 100th member of CU3
17/11: Nano-JASMINE and AGIS
27/10: Eclipsing binary light curves fitted with DPAC code
13/10: Gaia broad band photometry
28/09: Measuring stellar parameters and interstellar extinction
14/09: M1 mirror
27/08: Quest for the Sun's siblings
 
Please note: Entries from the period 2003-2010 are available in this PDF document.