Image of the Week


Gaia's Multi-dimensional Milky Way


Figure 1. A composition of Gaia sky maps, based on different Gaia data products from Gaia's third data release. Credits: ESA/Gaia/DPAC - CC BY-SA 3.0 IGO.​​​​​​ Acknowledgements: created by Tineke Roegiers, based on different Gaia sky maps created by ESA/Gaia/DPAC - CC BY-SA 3.0 IGO and inspired by NASA's Multiwavelength Milky Way Images.


Today marks the first anniversary of Gaia's data release 3 (Gaia DR3). The largest release published by the Gaia Collaboration so far, based on 34 months of data gathered between July 2014 and May 2017. The first batch of data was release already in December 2020, with Gaia's Early Data Release 3 (Gaia EDR3) and on 13 June 2022 the astrometry and photometry was complemented with numerous new data products such as extended objects and non-single stars.

The full Gaia DR3 catalogue consists of data on Milky Way sources, but also contains extragalactic data and information on Solar System Objects. While the large variety of data is hard to capture in a single figure, this composition of Gaia sky maps highlights the multi-dimensional Milky Way information available since last year.

The composition in the figure above was created from several Gaia Collaboration sky maps, as published on 13 June 2022. Below each sky map is provided with short caption and a link to a story discussing the type of data represented in that sky map.

Let's celebrate Gaia DR3's first anniversary!


Gaia' s stellar motion

The trails on this image show the displacement of stars on the sky 400 thousand years into the future. (Image for download, High resolution image for download) Credit: ESA/Gaia/DPAC, CC BY-SA 3.0 IGO. Acknowledgement: The image was created by Anthony Brown, based on an idea from Stefan Jordan, and with inputs from Tineke Roegiers, Xavier Luri, Eduard Masana, and Timo Prusti. Background colour image created by André Moitinho.

More information from the Gaia EDR3 story "Following the journey of stars across the sky" and from the press release of Gaia's Early Data Release 3.


Gaia's stellar ages


Sky map of stellar age obtained for Gaia Data Release 3, showing the average age of the stars in our Galaxy, with blue representing the younger stars and red representing the older stars. Most of the oldest stars are found outside the galactic disk. The age was derived with the Final Luminosity Age Mass Estimator (FLAME). Shown in this map is a random selection of 10 million stars from Gaia DR3. Credits: ESA/Gaia/DPAC - CC BY-SA 3.0 IGO. Acknowledgements: created by O.Creevey, M. Fouesneau, and the Gaia group at MPIA.

More information from the Gaia DR3 story "How big, warm, old, ... are the stars? - Gaia's Stellar parameters".


Gaia's brightnesses


Sky map of G-GRVS. Median G-GRVS colour in HEALpix 7, highlighting the effect of extinction by interstellar dust. GRVS is derived from the integration of the Radial Velocity Spectrometer spectra by the Coordination Unit 6 of DPAC. Credits: ESA/Gaia/DPAC - CC BY-SA 3.0 IGO. Acknowledgements: ESA/Gaia/DPAC/CU6, N. Leclerc, P. Sartoretti and the CU6 team.

More information from the Gaia DR3 story "How bright are the stars? - The Gaia DR3 magnitudes".


Gaia's variable stars


Map in galactic coordinates of about 134,000 RR Lyrae stars for which an estimate of metallicity was obtained from the pulsation period and the φ31 Fourier parameter of the G-band light curve. The sources are colour-coded according to their metallicity ([Fe/H]). The two Magellanic Clouds are easily recognized in the bottom-right portion of the map. The Sagittarius dwarf spheroidal galaxy popping out just below to the left from the centre of the map can also be clearly seen. The higher metallicity of the RR Lyrae stars in the Milky Way bulge compared to variables in the Galactic halo can easily be appreciated, as it is also clear the lower metal abundance of the RR Lyrae stars in the Small Magellanic Cloud compared to the variables in the Large Magellanic Cloud. Credits: ESA/Gaia/DPAC, CC BY-SA 3.0 IGO. Acknowledgements: ESA/Gaia/DPAC/CU7/CU6/CU5/INAF, Gisella Clementini, Alessia Garofalo, Tatiana Muraveva (INAF-OAS Bologna), Vincenzo Ripepi, Roberto Molinaro, Silvio Leccia (INAF-OACn Naples), and the CU7/DPCG, CU5, and CU6 teams.

More information in this Gaia DR3 preview story: "Not only distances: what Gaia DR3 RR Lyrae stars will tell us about our Galaxy and beyond" and in the Gaia DR3 story: "How do they blink? - The dimming and brightening of Gaia's variable stars" and from the press release of Gaia Data Release 3.


Gaia's stellar extinction


Sky map of GSPPhot extinction. GSPphot provides extinction for individual stars. These stars are combined into healpixels at level 10 to create these sky maps. The extinction is shown from A0 = 0 to 4 on the colour bar scale. In Gaia DR2 an extinction map using ~220 million sources binned into level 10 healpixels was shown. In this current map for Gaia DR3 ~470 million sources were used, binned into level 10 healpixels. This sky map has been smoothed. See Andrae et al., 2022 for more details. Note also that the colour map used here is different from that of the GSPphot Gaia DR2 images as published here and here. Details on the data used for this sky map: GSPphot - healpix level 10 data as available from the Gaia Archive. Credits: ESA/Gaia/DPAC - CC BY-SA 3.0 IGO. Acknowledgements: Created by T.E.Dharmawardena, Gaia group @ MPIA

More information from the Gaia DR3 story "What is in between the stars? - Gaia's view on dust and the interstellar medium" and from the press release of Gaia Data Release 3.


Gaia's map of the interstellar medium


This sky map shows the global distribution of the diffuse interstellar bands (DIB) colour coded by the equivalent width of the DIB at HEALPIx level 5 (~1.8 sq degree resolution). We see clearly strong DIBs concentrated towards the galactic plane. Clearly visible are also some extended features towards higher latitudes for the inner Galaxy (|l| < 30 degrees). Credits: ESA/Gaia/DPAC - CC BY-SA 3.0 IGO. Acknowledgements: ESA/Gaia/DPAC/CU8/GSP-SPec, created by H. Zhao and M. Schultheis.

More information from the Gaia DR3 story "What is in between the stars? - Gaia's view on dust and the interstellar medium".


Gaia's radial velocities

Sky map of the Gaia DR3 radial velocities. Download hires version here, without labels here. Compare to the same sky map from Gaia DR2 here. Credits: ESA/Gaia/DPAC- CC BY-SA 3.0 IGO. Acknowledgements: ESA/Gaia/DPAC/CU6, D. Katz, N. Leclerc, P. Sartoretti and the CU6 team.

More information from the Gaia DR3 story: "Do the stars approach us or do they move away? - The Gaia DR3 radial velocities bringing the third velocity component" and from the press release of Gaia Data Release 3.


Gaia's chemical map

All sky view in Galactic coordinates (HEALPix map) showing the stars in the Gaia DR3 GSP-Spec database (Gaia Collaboration, Recio-Blanco et al. 2022). The colour indicates the stellar metallicity, [M/H], that is the mean abundance of all chemical elements except hydrogen and helium. Redder stars are richer in metals. Credits: Gaia Data Release 3: Chemical cartography of the Milky Way by Gaia Collaboration et al. 2022. CC BY-SA 3.0 IGO.

More information from the Gaia DR3 story "What are the stars made of? - A chemical map with Gaia DR3" and from the press release of Gaia Data Release 3.


Gaia's three-dimensional stellar motion map

This sky map illustrates the measurements of the stellar velocities in the Milky Way using data from Gaia. The colour shows the line-of-sight velocity of stars. Blue shows the parts of the sky where the average radial motion of stars, relative to the Sun, is towards us, and red shows the regions of the sky where the average radial motion of stars is away from us. The lines overlaying the map show the streamlines of the proper motions of stars. These lines do not show the transverse motions of the stars in the Milky Way, but illustrate the proper motions as they are published in the catalogue, that is the right ascenscion and declination, projected onto the map in Galactic longitude and latitude. This artistic choice produces the line pattern, including the swirl on the left just above the galactic plane, and the 'peak' a the lower right.  The figure is also sensitive to the motion of the Sun within the Galaxy. The LMC and SMC are not visible because stars were selected with well defined distances.  The method used to generate the proper motion stream lines follows a modified version of a method from Okada & Kao (1997). The algorithm used was line integral convolution, from healpy. Credits: ESA/Gaia/DPAC - CC BY-SA 3.0 IGO. Acknowledgements: ESA/Gaia/DPAC/CU6, O.N. Snaith, P. Di Matteo, P. Sartoretti, N. Leclerc, D. Katz and the CU6 team. Download hires version here, without labels here.

More information from the Gaia DR3 story: "Do the stars approach us or do they move away? - The Gaia DR3 radial velocities bringing the third velocity component" and from the press release of Gaia Data Release 3.


Gaia's sky in colour


Data from more than 1.8 billion stars has been used to create this map of the entire sky. It shows the total brightness and colour of stars observed by ESA's Gaia satellite and released as part of Gaia's Early Data Release 3 (Gaia EDR3). Credits: ESA/Gaia/DPAC - CC BY-SA 3.0 IGO. Acknowledgements: A. Moitinho.

More information from the image release from the press release of Gaia's Early Data Release 3.


The many dimensions of Gaia Data Release 3

Next to the above sky maps, many more sky maps were published on 13 June 2022 with emphasis on other Gaia data products in the Milky Way but also extragalactic data like quasars and galaxies.  A larger selection of sky maps can be found in the below gif.

GIF running through sky maps based on the many different data products from Gaia Data Release 3. Two additional version are available; : without text / 1 sec per sky map and with text. Credits: ESA/Gaia/DPAC, CC BY-SA 3.0 IGO. Acknnowledgements: created by Tineke Roegiers, based on sky maps from the Gaia Collaboration.

More information from the Gaia DR3 stories.



There's a star map waiting in the sky... make sure to go and see it, cuz we think it will blow your minds

There's a star map waiting in the sky... we made sure not to blow it, cuz we know it's so worthwile

So... let the scientists search it... let the scientists use it... let the scientists boogie



Credits: ESA/Gaia/DPAC, T. Roegiers

[Published: 13/06/2023]

Image of the Week Archive


22/04: Gaia's contribution to discovering distant worlds

16/04: Gaia spots Milky Way's most massive black hole of stellar origin

02/04: The Gaia Cataclysmic Variable hook


19/12: 10 Science topics to celebrate Gaia's 10 years in space

31/10: Gaia observes cosmic clock inside a heavenly jewel

10/10: Gaia Focused Product Release stories

27/09: Does the Milky Way contain less dark matter than previously thought?

22/09: Mass-luminosity relation from Gaia's binary stars

13/09: Gaia DPAC CU8 seminars

13/06: Gaia's multi-dimensional Milky Way

18/05: Mapping the Milky Way

15/05: Goonhilly station steps in to save Gaia science data

25/04: The Gaia ESA Archive

05/04: Dual quasar found to be hosted by an ongoing galaxy merger at redshift 2.17

21/03: GaiaVari: a citizen science project to help Gaia variability classificaton

09/02: Missing mass in Albireo Ac: massive star or black hole?

31/01: Gaia reaches to the clouds – 3D kinematics of the LMC

25/01: Meet your neighbours: CNS5 - the fifth catalogue of nearby stars

18/01: A single-object visualisation tool for Gaia objects


25/11: 100 months of Gaia data

23/11: The astonishment

09/11: Gamma-Ray Burst detection from Lagrange 2 point by Gaia

04/11: Gaia's first black hole discovery: Gaia BH1

26/10: Are Newton and Einstein in error after all?

21/10: Gaia ESA Archive goes live with third data release

06/10: Mapping the interstellar medium using the Gaia RVS spectra

26/09: Gaia on the hunt for dual quasars and gravitational lenses

23/09: Gaia's observation of relativistic deflection of light close to Jupiter

13/06: Gaia Data Release 3

10/06: MK classification of stars from BP/RP spectrophotometry across the Hertzsprung-Russell diagram

09/06: BP/RP low-resolution spectroscopy across the Hertzsprung-Russell diagram

27/05: Cepheids and their radial velocity curves

23/05: The Galaxy in your preferred colours

19/05: GaiaXPy 1.0.0 released, a tool for Gaia's BP/RP spectra users

11/05: Systemic proper motions of 73 galaxies in the Local group

28/03: Gaia query statistics

16/03: Gaia's first photo shooting of the James Webb Space Telescope

08/03: Gaia's women in science - coordination unit 8

25/02: Not only distances: what Gaia DR3 RR Lyrae stars will tell us about our Galaxy and beyond

11/02: Gaia's women in science

31/01: Astrometric orbit of the exoplanet-host star HD81040

12/01: The Local Bubble - source of our nearby stars

05/01: A Milky-Way relic of the formation of the Universe


23/12: Signal-to-Noise ratio for Gaia DR3 BP/RP mean spectra

22/12: The 7 October 2021 stellar occultation by the Neptunian system

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

24/09: Astrometric microlensing effect in the Gaia16aye event

22/09: the power of the third dimension - the discovery of a gigantic cavity in space

16/09: An alternative Gaia sky chart

25/08: Gaia Photometric Science Alerts and Gravitational Wave Triggers

09/07: How Gaia unveils what stars are made of

23/06: Interviews with CU3

27/04: HIP 70674 Orbital solution resulting from Gaia DR3 processing

30/03: First transiting exoplanet by Gaia

26/03: Apophis' Yarkovsky acceleration improved through stellar occultation

26/02: Matching observations to sources for Gaia DR4


22/12: QSO emission lines in low-resolution BP/RP spectra

03/12: Gaia Early Data Release 3

29/10: Gaia EDR3 passbands

15/10: Star clusters are only the tip of the iceberg

04/09: Discovery of a year long superoutburst in a white dwarf binary

12/08: First calibrated XP spectra

22/07: Gaia and the size of the Solar System

16/07: Testing CDM and geometry-driven Milky Way rotation Curve Models

30/06: Gaia's impact on Solar system science

14/05: Machine-learning techniques reveal hundreds of open clusters in Gaia data

20/03: The chemical trace of Galactic stellar populations as seen by Gaia

09/01: Discovery of a new star cluster: Price-Whelan1

08/01: Largest ever seen gaseous structure in our Galaxy

20/12: The lost stars of the Hyades
06/12: Do we see a dark-matter like effect in globular clusters?
12/11: Hypervelocity star ejected from a supermassive black hole
17/09: Instrument Development Award
08/08: 30th anniversary of Hipparcos
17/07: Whitehead Eclipse Avoidance Manoeuvre
28/06: Following up on Gaia Solar System Objects
19/06: News from the Gaia Archive
29/05: Spectroscopic variability of emission lines stars with Gaia
24/05: Evidence of new magnetic transitions in late-type stars
03/05: Atmospheric dynamics of AGB stars revealed by Gaia
25/04: Geographic contributions to DPAC
22/04: omega Centauri's lost stars
18/04: 53rd ESLAB symposium "the Gaia universe"
18/02: A river of stars
21/12: Sonification of Gaia data
18/12: Gaia captures a rare FU Ori outburst
12/12: Changes in the DPAC Executive
26/11:New Very Low Mass dwarfs in Gaia data
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
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
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
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
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
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
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
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
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.