Tuesday, August 23, 2011

Eemian Globe

I've created a rotating globe modelled after the Eemian interglacial, ~125,000 years ago.

 


I've been using this model to illustrate a series of posts by Steve Brown on Skeptical Science:



My goal was to portray a plausible shape to the Eemian sea, which cut Scandinavia off from the mainland. While at it, I erased part of Florida (in case Eemian sea level reached the high estimate of 9 meters over current) and much of the deltas next to major rivers. Like all my projects, this is a work-in-progress and I invite comments and corrections.

jg

Monday, August 22, 2011

Circumhorizon Arc

My first circumhorizon arc:

 

 
I saw this at noon on Sunday, 8/21/11. The noon sighting is consistent with the description of this phenomena on Atmospheric Optics:
  • colorful ice halo from cirrus clouds refracting the overhead sun
  • location parallel to and near the horizon

jg

Friday, August 5, 2011

Star Party at Lake Skinner County Park, Saturday, 6 Aug. 2011

The Lake Skinner County Park is hosting a public star party. It is free, but you need to arrive after 7:00 pm when the normal entrance fee will be waived for this event only.  The star party is that the Park's amphitheater. A show begins at 8:00 pm and observing through the telescopes of the Temecula Valley Astronomers begins after the show at 8:30 (or earlier) and continues till 10:30 pm.

Primary targets will be the 1st quarter moon and Saturn and various star clusters of the summer Milky Way.

jg


Wednesday, August 3, 2011

Supernova update

Last weekend I had a chance to revisit the supernova in M51. I took a few photos before clouds obscured the view. Here is M51 with supernova marked by the arrow:

This is a very noisy image. It's a 5-minute exposure at f6.3 and 1600 ISO. I'm a little surprised that the supernova remains as bright as it is and that I recorded it this well in a single exposure through a 3-inch telescope.

I had planned to take several images and try stacking them, but I forgot to tighten the axis clamps on my mount, so this was the only picture that didn't have significant streiks for stars.

jg