The Moon on June 29th

Michael Milligan blogged his viewing of the Moon through the University of Minnesota's 10-inch refractor last evening. A great coincidence (aka clear skies for us both) had me at Ryerson viewing the Moon that evening too. It was a useful starting point to Saturn, Mars, and even the elusive Mercury. I also looked at Jupiter to add to the planet list.

I too photographed it, although I waited until the sun had set, taking the first image at 8:45PM with the intention of getting some of the twilight blue in the image.

This second image is a point-of-view image through the viewfinder.



Earlier I also branded a piece of wood with an "R" for Ryerson using the sun's setting rays.

The Antennae galaxy from Chicago

I am guessing that the Astronomy Picture of the Day for tomorrow, with the title "cosmic antennae", is likely to be about the Antennae Galaxy, an interacting pair 63 million light-years away in Corvus the Crow, visible now as a compact quadrilateral to the far lower-right of Jupiter blazing in the south after sunset. So, I'm posting a poor image of them now, because otherwise the APOD gets me every time in posting something I should have posted earlier.

I imaged the Antennae (also known as NGC 4038/4039) on April 26th from Ryerson Observatory. The total exposure time was about 85 minutes. My light-polluted skies overwhelmed the faint antennae structure of stars thrown out of the galaxies during the collision. I can see the individual superclusters of bright blue supergiants formed during intense starbirths from the compression of gas clouds during the collison. The two brightest knots in the galaxy (oriented roughly vertical in my image) are actually the cores of the original pre-collision galaxies.

Any variations in the dark gray background are dust donuts from the telescope, and leftovers of a smoothing feature I used to help get rid of the vignetting. My flats were not good enough to use for this processing.

A color illusion

Instructions: Keep your mouse out of the image. Stare at the center black dot for thirty seconds. Move mouse into image.

Click here for the illusion:
http://www.lib.uchicago.edu/~dean/blog/illusion.html

The idea is from John Sadowski
I need to find a better horizontal image for this illusion.

Pluto's new moons named: Nix and Hydra

I just saw on a cable TV news crawl that the IAU has named the two new moons of Pluto: Nix and Hydra.

Forbes article

Blog post about discovery

Cute:

"The 'P' and the 'L' in Pluto are in honor of the Percival Lowell, who instigated the search that resulted in the discovery of Pluto," Stern told Space.com. "The 'N' and the 'H' are exactly parallel to honor New Horizons which instigated the search that led us to [the new satellites]."

Info from the Southwest Research Institute

A triple junction in the Sky

D'oh! I started this entry two weeks ago, since it's such a fabulous image, of Regulus and Leo I, but never finished the entry and of course APOD covers it today.



I called the entry "A Triple Junction in the Sky" because of three distance scales that converge at this place in the sky. Leo I, being a (barely) extragalactic source, is that of all things outside of our own galaxy. It's not the farthest thing in the image; there are many angularly small galaxies that are quite a distance aways. The second scale is stellar: Regulus shines at 75 light-years away. One of the four Royal Stars of Persia, it quarters the sky with Aldebaran, Antares, and Fomalhaut.
The third scale, not visible in the image, is the the planetary scale. Regulus lies nearly on the ecliptic, the plane of the solar system, and the moon frequently occults Regulus. In fact other planetary objects can occult Regulus: the asteroid Rhodope covered it for a few seconds in Europe in 2005. Astronomers can use these occultations to measure the sizes of asteroids.

Be sure to see the large-sized image.
Image copyright: © 2005 Russell Croman, www.rc-astro.com

Yerkes Observatory sold

Sure enough, the University has sold Yerkes Observatory to Mirbeau Spa for $8 million. They get most of the land surrounding the observatory for their 72 house development and spa and donate the observatory building and nearby grounds to the city of Williams Bay, which has to agree to this. A non-profit will run the observatory, although the University is paying for the operation for 5 years and the claim is that special taxes of an unknown sort will fund the observatory's mission after that.

Chicago Tribune story archived via U of C News Office.

Official University Press Release

Yerkes Observatory News

I understand that a Yerkes Observatory decision has been made and one should expect an official announcement soon.

The Permian-Triassic Extinction: a source?

Ralph von Frese argues that a structure in the crust under Antarctica is a 500km wide impact crater and speculates that is was the source of the Permian-Triassic Extinction event which killed off 90% of all marine species.

Confirmation of this theory would require at least two things: the presence of shocked minerals near the impact crater, and dating of the crater to near the boundary (245 million years ago). It has been assumed by many that if there was an extraterrestial impact that caused the extinction it had hit in an ocean basin, and the evidence on the sea floor had long been subducted (the maximum age of oceanic crust in the Pacific is Jurassic in age).

Some images are here.

EDIT: There is some counter-arguments at Nature. Link via The Esoteric Science Resource Center.