February 2019 DFAC Update

quidnoviElectronic Newsletter of the
Desert Foothills Astronomy Club

Captain’s Log: February 6, 2019

Greetings Fellow Stargazers,

My apologies for this late publication. Been grappling with some computer and networking issues that ultimately required paid tech support. I rarely need assistance with any aspect of computing, so suffice it to say that this one was a tough nut to crack. I’ll spare you the details, but it came down to a conflict between antivirus software (now replaced) and Windows system drivers. And so it goes.

1. State of DFAC
The club status remains unchanged since the January Quid Novi. It appears no member is interested in any of the vacant, or about to be vacant, officer positions. After consultation with Treasurer Jay Chatzkel we have decided to use the remaining funds ($283.77) to renew our membership in the Astronomical League for another season when it comes due in June. This will continue our subscriptions to The Reflector newsletter, and maintain our visibility on their member societies page. The remainder will be donated to either the VOF or IDA. Dues will not be required this coming May, as the club will revert to an informal association of astronomers who can maintain contact and activities via our DFAC Events page. I’ll continue to run the website, and update our Events page until our hosting expires in March 2021.

2. VOF donation
Those with an eye for details may have noticed that our treasury funds are $50 less than what I reported last month. I received an email from VOF requesting donations to help the bridge a shortfall in donations this fiscal year. Br. Guy Consolmagno SJ hypothesizes that giving is down due to uncertainty about the future … political, economic, and climate-wise. So we sent a check to help them out.

3. Speckle interferometry
I shared an article on speckle interferometry from a recent issue of Physics Today with member (and expert speckle interferometrist) Richard Harshaw. He responded with “Yeah, I worked with that guy once” and suggested I also share it with the members. It’s an excellent explanation of the process and runs 1½ pages. You can read it here.

4. New addition to Astrophotos
Member Roger Serrato has been on an extended road trip that included Wyoming, where he got a great shot of Boötes setting over Devil’s Tower. No mother ship was seen. Check out his photo at the top of our Astrophotos page. Unfortunately, Roger did not include any astronomy info with his photo. So I used a handy tool that I recommended in Quid Novi a couple years ago: Astronomy.net. After uploading his photo their engine matched the starfield with its database and produced this chart. It’s a very cool tool if you have any old astrophotos you can’t identify. Regardless of image scale, orientation, flipping, or intrusion by an object or horizon, it will match your photo with the the correct starfield. Of course there is some processing time … this image took nearly 15 minutes.

5. Astronomical Eye Candy
For those of you who don’t regularly follow my Sky Lights blog, I present a recent animation done to show how Ultima Thule may have formed. The idea was to simulate a low velocity impact that conserved angular momentum and results in the object’s observed rotation period of 15±1 hours (obviously not in real-time). I also wanted to show how the bright ring at the point of contact likely formed. The outer layer of Ultima Thule has been “weathered” by cosmic radiation to the color of potting soil. The collision that joined the two bodies splashed fresh ice from below the crust, some of which settled around the point of impact. Enjoy.

Till next we meet, clear skies.

Dan Heim
Desert Foothills Astronomy Club