V 372 Orionis

V 372 Orionis, just below the center of this frame, is an odd type of variable star known as an Orion Variable. These young stars experience irregular variations in luminosity. Orion Variables are often associated with diffuse nebulae, and V 372 Orionis is no exception; the patchy gas and dust of the Orion Nebula pervade this image.

Image Credit: ESA / NASA

M32 and M110

The Andromeda Galaxy (aka Messier 31) has several satellite galaxies. The best known are M32 and M110.  M32 probably underwent a close encounter with Andromeda Galaxy and had its stellar disk removed by M31. That encounter caused a sharp increase of star formation in M32’s core region. M32 is the large galaxy near the center of the image.

M110 is the smaller galaxy below and to the right of MN32. It also appears to be interacting with the Andromeda Galaxy. Astronomers have found in the large galaxy’s halo a stream of metal-rich stars that appear to have been stripped from the satellite galaxies.

Image Credit: Torben Hansen, CC BY 2.0

Titan and Rhea

Titan and RheaSaturn’s two largest moons, Titan and Rhea, seem to be stacked together in this true-color picture taken by the Cassini spacecraft. This view looks toward the Saturn-facing side of Rhea. North on Rhea is up and rotated 35 degrees to the right.

Separate images taken with red, green and blue filters using Cassini‘s narrow-angle camera were combined to create this natural-color view. The spacecraft was approximately 1.8 million km away from Rhea and 2.5 million km from Titan.

Image Credit: NASA

Messier 2

Messier_2Messier 2 (aka M2) is about 37,500 light-years from Earth. It is roughly 175 light-years in diameter, one of the larger globular clusters known. It is 13 billion years old and one of the older globulars associated with the Milky Way Galaxy. M2 contains about 150,000 stars, including 21 known variable stars. Its brightest stars are red and yellow giant stars. Click the image to embiggen it. It’s 4k X 4k pixels, so, depending on your browser, a second click may be necessary to get it to full size.

Image Credit: NASA

Dense Dwarfs

Ultra-compact dwarf galaxies are a class of very compact galaxies with very high stellar densities. An extreme example of a UCD is M60-UCD1 which contains approximately 200 million solar masses within a 160 light-year radius. The stars in its cental region are about 25 times closer together than the stars in our part of the Milky Way. M59-UCD3 is approximately the same size as M60-UCD1 with a half-light radius, but it’s 40% more luminous. This makes M59-UCD3 the densest known galaxy.

Image Credit: NASA

A View From Mars

earth-from-mars-hiresA telescope in orbit around Mars took this view of Earth and its Moon, showing continent-size detail on the planet. The image combines two separate exposures taken in November, 2016, by the High Resolution Imaging Science Experiment (HiRISE) camera on the Mars Reconnaissance Orbiter. The images were taken to calibrate HiRISE  using the known value of reflectance for the Earth-facing side of the Moon. The exposures used to make this composite image were processed separately to optimize detail visible on both Earth and the Moon. The Moon is much darker than Earth and would barely be visible if shown at the same brightness scale as Earth.

The combined view retains the correct positions and sizes of the two bodies relative to each other. The distance between Earth and the Moon is about 30 times the diameter of Earth. Earth and the moon appear closer than they actually are in this image because the observation was planned for a time at which the Moon was almost directly behind Earth as seen from Mars so that the Earth-facing side of the Moon would be visible.

The reddish feature near the middle of the face of Earth is Australia. Mars was about 205 million km from Earth when the images were taken, so nude sunbathers are not visible in this image.

Image Credit: NASA

X-Ray Vision

chandra-deep-field-southThis image was made with over 7 million seconds (about 11-1/2 weeks) of Chandra X-Ray Observatory observing time. It’s part of the Chandra Deep Field-South and is the deepest X-ray image ever obtained. This look at the early Universe in X-rays gives astronomers the best look yet at the growth of black holes over billions of years starting soon after the Big Bang. In this image, low, medium, and high-energy X-rays that Chandra detects are shown as red, green, and blue respectively.

Image Credit: NASA

A Fading Singray

This video shows how the planetary nebula Hen 3-1357 (aka the Stingray Nebula) has faded since the mid 1990s. The nebula is first seen as photographed by the Hubble Space Telescope in 1996, with filaments and tendrils of gas glowing bright blue at its center. Then it transitions to Hubble’s 2016 image, which shows a much dimmer nebula lacking in the pronounced wavy edges.

Video Credit: NASA / ESA/ STScI

Another Cat Picture on the Web

The Cat's Paw RemasteredNot the whole cat, just his paw. This is the Cat’s Paw Nebula (aka NGC 6334). It’s found in the constellation of Scorpius (The Scorpion). Although it appears to be close to the center of the Milky Way in the sky, it is relatively near to Earth, about 5500 light-years away. It’s about 50 light-years across.

The Cat’s Paw is one of the most active star formation regions in the galaxy, containing massive, brilliant blue stars which have formed within the last few million years. It probably contains on the order of ten thousand stars. but many are hidden from view by the dust clouds fueling the rapid star formation.

Image Credit: ESO

BTW, not all catspaws are in space.