Astronomy Picture of the Day for June 15

Discover the cosmos!Each day a different image or photograph of our fascinating universe is  featured, along with a brief explanation written by a professional astronomer.

2012 June 15

M65 and M66

Image Credit & Copyright: Bill Snyder (Heavens Mirror Observatory)

Explanation: Nearby and bright, spiral galaxies M65 (top) and M66 stand out in this engaging cosmic snapshot. The pair are just 35 million light-years distant and around 100,000 light-years across, about the size of our own spiral Milky Way. While both exhibit prominent dust lanes sweeping along their broad spiral arms, M66 in particular is a striking contrast in red and blue hues; the telltale pinkish glow of hydrogen gas in star forming regions and young blue star clusters. M65 and M66 make up two thirds of the well-known Leo Triplet of galaxies with warps and tidal tails that offer evidence of the group’s past close encounters. The larger M66 has been host to four supernovae discovered since 1973.

Astronomy Picture of the Day for February 11

Astronomy Picture of the Day

Discover the cosmos!Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2012 January 17
See Explanation.  Clicking on the picture will download the highest resolution version available.

IC 2118: The Witch Head Nebula
Image Credit & Copyright: Gimmi Ratto & Davide Bardini (Collecting Photons) 

 

Explanation: Double, double toil and trouble; Fire burn, and cauldron bubble — maybe Macbeth should have consulted the Witch Head Nebula. This suggestively shaped reflection nebula is associated with the bright star Rigel in the constellation Orion. More formally known as IC 2118, the Witch Head Nebula glows primarily by light reflected from bright star Rigel, located just below the lower edge of the above image. Fine dust in the nebula reflects the light. The blue color is caused not only by Rigel’s blue color but because the dust grains reflect blue light more efficiently than red. The same physical process causes Earth’s daytime sky to appear blue, although the scatterers in Earth’s atmosphere are molecules of nitrogen and oxygen. The nebula lies about 1000 light-years away.