The smoking gun of a newborn star: In this image the NASA/ESA Hubble Space Telescope has captured the smoking gun of a newborn star, the Herbig–Haro objects numbered 7 to 11 (HH 7–11). These five objects, visible in blue in the top centre of the image, lie within NGC 1333, a reflection nebula full of gas and dust found about a thousand light-years away from Earth. Herbig-Haro objects like HH 7–11 are transient phenomena. Travelling away from the star that created them, at a speed of up to 250 000 kilometres per hour they disappear into nothingness within a few tens of thousands of years. The young star that is the source of HH 7-11 is called SVS 13 and all five objects are moving away from SVS 13 toward the upper left. The current distance between HH 7 and SVS 13 is about 20 000 times the distance between Earth and the Sun. Herbig–Haro objects are formed when jets of ionised gas ejected by a young star collide with nearby clouds of gas and dust at high speeds. The Herbig-Haro objects visible in this image are no exception to this and were formed when the jets from the newborn star SVS 13 collided with the surrounding clouds. These collisions created the five brilliant clumps of light within the reflection nebula.

Name: 2MASS J03285694+3116222
Type: Milky Way : Nebula : Type : Star Formation
Category: Nebulae
Constellation: Perseus
Distance: 800 light years
Release date: 31 December 2018, 06:00
Credit: ESA/Hubble & NASA, K. Stapelfeldt

The heart of the Lion: It might appear featureless and unexciting at first glance, but NASA/ESA Hubble Space Telescope observations of this elliptical galaxy — known as Messier 105 — show that the stars near the galaxy’s centre are moving very rapidly. Astronomers have concluded that these stars are zooming around a supermassive black hole with an estimated mass of 200 million Suns! This black hole releases huge amounts of energy as it consumes matter falling into it and causing the centre to shine far brighter than its surroundings. This system is known as an active galactic nucleus. Hubble also surprised astronomers by revealing a few young stars and clusters in Messer 105, which was thought to be a “dead” galaxy incapable of star formation. Messier 105 is now thought to form roughly one Sun-like star every 10 000 years. Star-forming activity has also been spotted in a vast ring of hydrogen gas encircling both Messier 105 and its closest neighbour, the lenticular galaxy NGC 3384. Messier 105 was discovered in 1781, lies about 30 million light-years away in the constellation of Leo (The Lion), and is the brightest elliptical galaxy within the Leo I galaxy group.

Name: M 105, Messier 105
Type: Early Universe : Galaxy : Type : Elliptical
Category: Galaxies
Constellation: Leo
Distance: 30 million light years
Release date: 7 January 2019, 06:00
Credit: ESA/Hubble & NASA, C. Sarazin et al.

Messier Monday: This huge ball of stars — around 100 billion in total — is an elliptical galaxy located some 55 million light-years away from us. Known as Messier 89, this galaxy appears to be perfectly spherical; this is unusual for elliptical galaxies, which tend to be elongated ellipsoids. The apparently spherical nature of Messier 89 could, however, be a trick of perspective, and be caused by its orientation relative to the Earth. Messier 89 is slightly smaller than the Milky Way, but has a few interesting features that stretch far out into the surrounding space. One structure of gas and dust extends up to 150 000 light-years out from the galaxy’s centre, which is known to house a supermassive black hole. Jets of heated particles reach out to 100 000 light-years from the galaxy, suggesting that Messier 89 may have once been far more active — perhaps an active quasar or radio galaxy — than it is now. It is also surrounded by an extensive system of shells and plumes, which may have been caused by past mergers with smaller galaxies — and implies that Messier 89 as we know it may have formed in the relatively recent past. Messier 89 was discovered by astronomer Charles Messier in 1781, when Messier had been cataloguing astronomical objects for 23 years — ever since he mistook a faint object in the sky for Halley’s Comet. Upon closer inspection, he realised the object was actually the Crab Nebula. To prevent other astronomers from making the same error, he decided to catalogue all the bright, deep-sky objects that could potentially be mistaken for comets. His methodical observations of the night sky led to the first comprehensive catalogue of astronomical objects: the Messier catalogue! Messier 89 holds the record for being the last ever giant elliptical to be found by Messier, and the most perfectly spherical galaxy in the entire catalogue of 110 objects.

Name: Messier 89
Type: Local Universe : Galaxy : Type : Elliptical
Category: Galaxies
Constellation: Virgo
Release date: 14 January 2019, 06:00
Credit: ESA/Hubble & NASA, S. Faber et al.

Peering into the past: This picture showcases a gravitational lensing system called SDSS J0928+2031. Quite a few images of this type of lensing have been featured as Pictures of the Week in past months, as NASA/ESA Hubble Space Telescope data is currently being used to research how stars form and evolve in distant galaxies. Gravitational lensing can help astronomers study objects that would otherwise be too faint or appear too small for us to view. When a massive object — such as a massive cluster of galaxies, as seen here — distorts space with its immense gravitational field, it causes light from more distant galaxies to travel along altered and warped paths. It also amplifies the light, making it possible for us to observe and study its source. In this image, we see two dominant elliptical galaxies near the centre of the image. The gravity from the galaxy cluster that is the home of these galaxies is acting as the aforementioned gravitational lens, allowing us to view the more distant  galaxies sitting behind them. We see the effects of this lensing as narrow, curved streaks of light surrounding both of the large galaxies. This image was observed by Hubble as part of the Sloan Giant Arcs Survey programme.

Name: SDSS J0928+2031
Type: Early Universe : Cosmology : Phenomenon : Lensing
Category: Galaxies
Constellation: Leo
Release date: 21 January 2019, 06:00
Credit: ESA/Hubble & NASA, M. Gladders et al.Acknowledgement: Judy Schmidt