Taking a third look

Messier 96

A spiral galaxy, tilted nearly face-on to us, with a slightly unusual shape. Its spiral arms form an oval-shaped ring around the galaxy’s disc, filled with blue light from stars, as well as pink glowing gas bubbles where new stars are forming. Threads of dark red dust swirl around the brightly glowing core, blocking some of its light. The dust lanes extend into and follow the spiral arms. Credit: ESA/Hubble & NASA, F. Belfiore, D. Calzetti

Today’s NASA/ESA Hubble Space Telescope Picture of the Week features a galaxy whose asymmetric appearance may be the result of a galactic tug of war.Located 35 million light-years away in the constellation Leo, the spiral galaxy Messier 96 is the brightest of the galaxies in its group. The gravitational pull of its galactic neighbours may be responsible for Messier 96’s uneven distribution of gas and dust, asymmetric spiral arms, and off-centre galactic core.

This asymmetric appearance is on full display in a new Hubble image, which incorporates observations made in ultraviolet and optical light. Hubble images of Messier 96 have been released previously in 2015 and 2018. Each successive image has added new data, building up a beautiful and scientifically valuable view of the galaxy.

This third version gives an entirely new perspective on Messier 96’s star formation. The bubbles of pink gas in this image surround hot, young, massive stars, illuminating a ring of star formation in the outskirts of the galaxy. These young stars are still embedded within the clouds of gas from which they were born. The new data included for the first time in this image will be used to study how stars are born within giant dusty gas clouds, how dust filters starlight, and how stars affect their environments.

Source: ESA/Hubble/potw

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Portrait of an Imperfect but Beautiful Spiral

NGC 3368 - Messier 96
Credit: ESO/Oleg Maliy

Not all spiral galaxies have to be picture-perfect to be striking. Messier 96, also known as NGC 3368, is a case in point: its core is displaced from the centre, its gas and dust are distributed asymmetrically and its spiral arms are ill-defined. But this portrait, taken with the FORS1 instrument on ESO’s Very Large Telescope, shows that imperfection is beauty in Messier 96. The galaxy's core is compact but glowing, and the dark dust lanes around it move in a delicate swirl towards the nucleus. And the spiral arms, patchy rings of young blue stars, are like necklaces of blue pearls.

Messier 96 lies in the constellation of Leo (The Lion). It is the largest galaxy in the Leo I group of galaxies; including its outermost spiral arms, it spans some 100 000 light-years in diameter — about the size of our Milky Way. Its graceful imperfections likely result from the gravitational pull of other members in the group, or are perhaps due to past galactic encounters.

A multitude of background galaxies peers through the dusty spiral. Perhaps the most striking of these objects is an edge-on galaxy that — because of a chance alignment — appears to interrupt the outermost spiral arm to the upper left of Messier 96's core.

This image was processed by ESO using the observational data found by Oleg Maliy from Ukraine, who participated in ESO's Hidden Treasures 2010 astrophotography competition [1], organised in October–November 2010, for everyone who enjoys making beautiful images of the night sky using astronomical data obtained with professional telescopes. The image was made with data taken at visible and infrared wavelengths through B, V, and I filters.

Notes

[1] ESO’s Hidden Treasures 2010 competition gave amateur astronomers the opportunity to search through ESO’s vast archives of astronomical data, hoping to find a well-hidden gem that needed polishing by the entrants. To find out more about Hidden Treasures, visit http://www.eso.org/public/outreach/hiddentreasures/.