X rays From HCG 62
8.03.2001

Scanning the skies for galaxies Canadian astronomer Paul Hickson and colleagues identified some 100 compact groups of galaxies, now appropriately called Hickson Compact Groups (HCGs). With only a few member galaxies per group, HCGs...

X Ray Rainbows
11.05.2001

A drop of water or prism of glass can spread out visible sunlight into a rainbow of colors. In order of increasing energy, the well known spectrum of colors in a rainbow runs red, orange, yellow, green, blue, indigo, violet.

X Ray Rainbows
28.09.2002

A drop of water or prism of glass can spread out visible sunlight into a rainbow of colors. In order of increasing energy, the well known spectrum of colors in a rainbow runs red, orange, yellow, green, blue, indigo, violet.

M27: Not a Comet
26.08.2010

While hunting for comets in the skies above 18th century France, astronomer Charles Messier diligently kept a list of the things he encountered that were definitely not comets. This is number 27 on his now famous not-a-comet list.

Mars in the Loop
9.08.2012

This composite of images spaced some 5 to 7 days apart from late October 2011 (top right) through early July 2012 (bottom left), traces the retrograde motion of ruddy-colored Mars through planet Earth's night sky.

Arp 299: Black Holes in Colliding Galaxies
31.10.2016

Is only one black hole spewing high energy radiation -- or two? To help find out, astronomers trained NASA's Earth-orbiting NuSTAR and Chandra telescopes on Arp 299, the enigmatic colliding galaxies expelling the radiation.

NGC 7822: Cosmic Question Mark
12.10.2021

It may look like a huge cosmic question mark, but the big question really is how does the bright gas and dark dust tell this nebula's history of star formation. At the edge...

Aurigae Nebulae
24.02.2012

Rich in star clusters and nebulae, the ancient constellation of Auriga, the Charioteer, rides high in northern winter night skies. Composed from narrow and broadband filter data and spanning nearly 8 Full Moons (4 degrees) on the sky, this deep telescopic view recorded in January shows off some of Auriga's celestial bounty.

Solar Neutrino Astronomy
17.05.2001

Neutrinos are subatomic particles generated by the nuclear reactions which power stars like our Sun. Flying outward from the Sun's core, they easily pass through the Sun (and almost anything else!) unimpeded and should be detectable by earth-based neutrino "telescopes".

Rho Ophiuchi Wide Field
12.05.2019

The colorful clouds surrounding the star system Rho Ophiuchi compose one of the closest star forming regions. Rho Ophiuchi itself is a binary star system visible in the blue reflection nebula just to the left of the image center.