Gaia satellites create the most detailed and accurate maps of the Milky Way galaxy
REPUBLIKA.CO.ID, PARIS – The most accurate three-dimensional map of the Milky Way Galaxy reveals the secrets of our galaxy. Peering deep into the anticenter (the opposite direction from the galactic center) helps astronomers piece together the Milky Way’s wild past.
The European Space Agency’s Gaia satellite, launched in 2013, has been working for years to map the galaxy. Gaia strives to create maps with the most detailed and highest possible precision.
Its new data release, Gaia Early Data Release 3 (EDR3), is a major improvement to existing data, as demonstrated in a series of new papers published at Astronomy & Astrophysics.
In addition to investigating galactic anticentres, astronomers have described the orbits of the Solar System around the galactic center. Astronomers observe the Magellanic Cloud orbiting the Milky Way, and carry out the largest census of the Milky Way’s stars and their movements in the sky.
“The new Gaia data promises to be a treasure trove for astronomers,” said ESA astronomer Jos de Bruijne. Science Alert, Saturday (5/12).
Gaia orbits the Sun with Earth, in a circular orbit around the Sun-Earth Lagrangian point L2, a gravitational stable pocket of space created by the interactions between two objects.
From there, Gaia studied the Milky Way’s stars closely over a long period of time. Gaia observed how the position of the stars seemed to change with respect to stars that were further away. It provides parallax, which can be used to calculate the distance to the stars.
It can be done from here on Earth, but atmospheric effects can interfere with measurements. From his position in space, Gaia has an edge, which he has put to excellent use.
To date, Gaia has mapped 1.8 billion sources in detail, and collected color information on 1.5 billion sources. According to the European Space Agency (ESA), that’s an increase of 100 million and 200 million sources from Data Release 2 in 2018.
What is interesting is anticentre Milky Way. This region is not as densely populated as the galactic center, nor is it covered by a thick cloud of interstellar dust, providing a clearer view of the stars on the edge of the Milky Way.
This region shows more clearly the disturbance caused to the Milky Way throughout its history. Astronomers conclude that the galactic disk used to be smaller than it is today.
Interestingly, an older star, the Milky Way’s original population, does not extend as far as stars from the Gaia Sausage, the galaxy that merged with the Milky Way 8 to 10 billion years ago.
When looking above and below the galactic plane, a different picture emerges. The group of stars above the plane is moving downwards, and the stars below are moving upwards.
According to the analysis, this could be the result of a slow and sustained collision with the dwarf galaxy Sagittarius, ruffling the outer edge of the Milky Way’s disk.
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