A cosmic quartet

Space can be a lonely place. But not so for this quartet of galaxies making up HCG 86 and observed here with ESO’s VLT Survey Telescope (VST). The four galaxies located approximately 270 million light years from Earth in the Sagittarius constellation, are seen from Earth as arranged in triangular shape, with three of them on a straight line and one underneath; the bright objects to the right of the elongated galaxy are not part of the quartet.

HCG stands for Hickson Compact Group, and is used to describe groups of four to ten galaxies where members are physically very close to each other. Because of their compactness, such groups are ideal environments to study galactic interactions, which can sometimes lead to galaxies merging with each other.  

This image of HCG 86 was taken by a team of astronomers led by Rossella Ragusa of the Istituto Nazionale di Astrofisica in Italy as part of the VST Early-type Galaxy Survey (VEGAS) programme. “With VST we are able to investigate very faint structures in the galaxies' outskirts, which are the relics of past gravitational interactions and merging events,” says Ragusa. In particular, by mapping the light distribution in and around the group’s galaxies in this study, the team concluded that these faint structures are the leftovers of satellite galaxies gobbled by the group approximately seven billion years ago.

Located at ESO’s Paranal Observatory in Chile, the VST is one of the world’s largest survey telescopes, devoted to mapping the sky in visible light wavelengths. 2021 marks the anniversary of its first decade of operation, a period during which it has helped to search for planets outside the Solar System and probe the structure of our galaxy and the wider Universe.

Kilde:

ESO/Ragusa, Spavone et al.

Om bildet

ID:potw2130a
Type:Observasjon
Publiseringsdato:26. juli 2021 06:00
Størrelse:4691 x 3229 px

Om objektet

Navn:HCG 86
Type:Local Universe : Galaxy : Type : Interacting
Avstand:270 million lysår
Constellation:Sagittarius
Kategori:Galaxies

Bildeformater

Stor JPEG
2,1 MB
Medium JPEG
197,5 KB

Zoombart


Skrivebordsbakgrunner

1024x768
255,5 KB
1280x1024
349,6 KB
1600x1200
454,2 KB
1920x1200
512,7 KB
2048x1536
636,4 KB

Koordinater

Position (RA):19 51 59.28
Position (Dec):-30° 49' 32.80"
Field of view:15.64 x 10.76 arcminutes
Orientering:Nord er -0.0° til venstre for vertikalen

Farger og filtre

BåndBølgelengdeTeleskop
Optisk
g
480 nmVLT Survey Telescope
OmegaCAM
Optisk
r
625 nmVLT Survey Telescope
OmegaCAM
Optisk
i
770 nmVLT Survey Telescope
OmegaCAM