July 26, 2016

The Cat's Paw Nebula

The Cat's Paw Nebula

The Cat’s Paw Nebula (NGC 6334) is a vast region of star formation. This new portrait of NGC 6334 was created from images taken with the Wide Field Imager instrument at the 2.2-metre MPG/ESO telescope at the La Silla Observatory in Chile, combining images taken through blue, green and red filters, as well as a special filter designed to let through the light of glowing hydrogen. NGC 6334 lies about 5500 light-years from Earth in the constellation of Scorpius. The whole gas cloud is about 50 light-years across.

NGC 6334 is one of the most active nurseries of massive stars in our galaxy and has been extensively studied by astronomers. The nebula conceals freshly minted brilliant blue stars — each nearly ten times the mass of our Sun and born in the last few million years. The region is also home to many baby stars that are buried deep in the dust, making them difficult to study. In total, the Cat’s Paw Nebula could contain several tens of thousands of stars.

The nebula appears red because its blue and green light are scattered and absorbed more efficiently by material between the nebula and Earth. The red light comes predominantly from hydrogen gas glowing under the intense glare of hot young stars.

Image Credit: ESO
Explanation from: https://www.eso.org/public/images/eso1003a/

The UGC 5497 Galaxy

dwarf galaxy UGC 5497

The NASA/ESA Hubble Space Telescope has captured this view of the dwarf galaxy UGC 5497, which looks a bit like salt dashed on black velvet in this image.

The object is a compact blue dwarf galaxy that is infused with newly formed clusters of stars. The bright, blue stars that arise in these clusters help to give the galaxy an overall bluish appearance that lasts for several million years until these fast-burning stars explode as supernovae.

UGC 5497 is considered part of the M 81 group of galaxies, which is located about 12 million light-years away in the constellation Ursa Major (The Great Bear). UGC 5497 turned up in a ground-based telescope survey back in 2008 looking for new dwarf galaxy candidates associated with Messier 81.

According to the leading cosmological theory of galaxy formation, called Lambda Cold Dark Matter, there should be far more satellite dwarf galaxies associated with big galaxies like the Milky Way and Messier 81 than are currently known. Finding previously overlooked objects such as this one has helped cut into the expected tally — but only by a small amount.

Astrophysicists therefore remain puzzled over the so-called "missing satellite" problem.

The field of view in this image, which is a combination of visible and infrared exposures from Hubble’s Advanced Camera for Surveys, is approximately 3.4 by 3.4 arcminutes.

Image Credit: ESA/Hubble & NASA
Explanation from: https://www.spacetelescope.org/images/potw1224a/

Artist’s impression of a hot Jupiter exoplanet in the star cluster Messier 67

Artist’s impression of a hot Jupiter exoplanet in the star cluster Messier 67

This artist’s impression shows a hot Jupiter planet orbiting close to one of the stars in the rich old star cluster Messier 67, in the constellation of Cancer (The Crab). Astronomers have found far more planets like this in the cluster than expected. This surprise result was obtained using a number of telescopes and instruments, among them the HARPS spectrograph at ESO’s La Silla Observatory in Chile. The denser environment in a cluster will cause more frequent interactions between planets and nearby stars, which may explain the excess of hot Jupiters.

Image Credit: ESO/L. Calçada
Explanation from: http://www.eso.org/public/images/eso1621a/