Category Archives: galaxies

galaxies, griffith observatory, markarian's chain, the big picture

The Big Picture

3 Comments

An Introduction to Large-Scale Structure

Markarians Chain, part of the Virgo Cluster of galaxies, as seen in The Big Picture. Courtesy of the Palomar-Quest Team, California Institute of Technology. (Click to embiggen.)
Markarian's Chain, part of the Virgo Cluster of galaxies, as seen in The Big Picture. Courtesy of the Palomar-Quest Team, California Institute of Technology. (Click to embiggen.)

One of the coolest exhibits I’ve ever seen is taking up a wall at the Griffith Observatory in Los Angeles, California. It’s called The Big Picture, and is a deep view of a very small region in the constellation Virgo. It was taken using the Samuel Oschin Telescope on Palomar Mountain in California.

What makes this picture amazing is that it is a single continuous digital sky image, portrayed in porcelain tiles. It has at least a million galaxies and thousands of quasars depicted in it, plus asteroids, and a comet.  The galaxies are part of the Virgo Cluster, the nearest big cluster to our own Local Group of Galaxies. Beyond them are the other galaxies, all part of the large-scale structure of the universe.

The Big Picture is the focus of today’s 365 Days of Astronomy podcast — which Mark and I produced. So, go over and check it out. I’ve also got a related page about it and the large-scale structure of the cosmos, here.

You can also see a video I’ve produced about The Big Picture as part of Astrocast.TV starting on May 1. I’ve joined the crew of Astrocast.tv to produce a monthly segment called The Astronomer’s Universe. Either way, be sure and check out this amazing image–it’ll take your breath away.

Arp 194, astronomy, astronomy news, astronomy research, galaxies, galaxy interactions

Celebrating 19 Years of Hubble Space Telescope

Leave a comment

Wow!!!

Arp 194 -- two colliding galaxies, a streamer of star birth and a background galaxy -- all shown by HST. (Click to embiggen.)
Arp 194 -- two colliding galaxies, a streamer of star birth and a background galaxy -- all shown by HST. (Click to embiggen.)

HST is probably the undisputed champion imager of colliding galaxies. For 19 years it’s been showing us the view as distant things go “bump” in the night. So, it’s only natural that the folks at Space Telescope Science Institute and the European Hubble office would celebrate the telescope’s 19th year on orbit with a smashing image of galaxy collision.  This one’s a doozy, folks!

This image actually shows a trio of galaxies, only two of which are doing the actual interacting.  The trio is called Arp 194, At first glance, it looks like one of them has sprung a leak. The bright blue streamer is really a stretched spiral arm full of newborn blue stars.  You see these a lot during the aftermath of galaxy collisions and this is easily one of the most impressive ‘star fountain’ formations I’ve ever seen.

The two nuclei of the colliding galaxies can be seen in the process of merging at the upper left — they look like a pair of owl eyes. The blue bridge looks like it connects to a third galaxy. In reality the galaxy is in the background and not connected at all — although astronomers aren’t sure yet if there is any interaction between it and the northern pair of galaxies (which are interacting). Hubble’s sharp view allows astronomers to try and visually sort out what are foreground and background objects when galaxies, superficially, appear to overlap.

This whole scene is playing out about 600 million light-years from us, in the direction of the constellation Cepheus. The region has a number of interesting galaxy interactions, so this little galactic birthday party will likely not be the last that HST sees.

I must say, this is a great birthday card for HST. The telescope’s accomplishments are many: during the past 19 years Hubble has made more than 880,000 observations and snapped over 570,000 images of 29,000 celestial objects.