by Rex Parker, Phd email@example.com
Transits and much more
Last meeting of the year coming up at Peyton Hall. See Ira’s section for more about the next guest speaker. It’s been another year of great presentations and discussions at AAAP. We certainly covered a lot of space, with perhaps more focus on our solar system than in other years that I can remember — from the Apollo moon landing with its undeniable nostalgia, to the edges of the solar system out to the mysterious Oort Cloud where long period comets originate.
The Mercury transit on the morning of November 11, 2019 was seen by several members at the AAAP Observatory in Washington Crossing Park (picture below). After a week of rains and cloudy weather the skies cleared before sunrise and the transit was completely visible in the telescopes set up with solar filters. It’s fortunate too, since the next one visible in the northern hemisphere will be in 2049. The Mercury transit was a perfect lead-in to the talk by Prof. Joshua Winn the very next night about transiting exoplanets. We learned how transits of exoplanets around nearby stars are the basis of the Kepler and TESS orbiting telescope projects. It’s amazing to see how much is being determined from the transit measurements (especially after viewing the Mercury transit), including orbital period, distance from the star, and size of the exoplanet. These emerging data are setting the stage for the upcoming James Webb Space Telescope with one of its primary goals the search for bio-signatures of potentially life-bearing exoplanets. We’re witnessing amazing advances in astronomy and the beginnings of astrobiology right before our eyes.
AAAP members at the Observatory Nov 11 for the Mercury Transit.
Seeking new co-editor for Sidereal Times
The departure of Prasad Ganti, whose efforts on the “Official Publication of AAAP” will be greatly missed, creates an opportunity for a new co-editor. The role is to organize and edit member submissions, and do the layout using WordPress software for uploading to the website. The responsibility would be shared with Surabhi Agarwal, who also serves as AAAP webmaster along with John Miller. Experience with WordPress is helpful but not necessary as you will quickly learn the skills and software. More importantly the position requires an affinity for astronomy and writing, with creativity and a willingness to contribute to others’ knowledge while gaining internet editing experience. If interested please contact Surabhi or me (firstname.lastname@example.org or email@example.com).
You could give the next 10 minute talk
We’re hoping to hear from you about giving a short talk in an upcoming monthly meeting at Peyton Hall. These are slotted for about 10 minutes following intermission after the main speaker. You can share tales of your recent astronomy-related experiences, perhaps a book review, travel to a science museum, what you observed in your telescope, new eyepieces or gizmos you’ve acquired. Slides are optional (bring a USB module and use the laptop up front). Contact me or Ira (firstname.lastname@example.org) to get onto the schedule.
Visitors from the stars
At the November meeting I described an interesting new discovery of another interstellar visitor. This is in the wake of Oumuamua, a name taken from Hawaiian which means “scout” or “messenger visiting from the past”. Its astronomical designation is less romantic, 1I/2017 U1. Originally thought to be a comet, Oumuamua was determined to be a very unusual asteroid. It created a stir in the astronomy community when it entered and swiftly left the solar system in the fall of 2017. Measurements released by NASA and other astronomers showed a length of perhaps 1000m and width of ~100m, an elongated shape never before seen for solar system objects. It had a very high speed which cannot be naturally achieved by objects originating in the solar system. These observations led to the interesting speculation that Oumuamua could be an alien space ship traveling between the stars. The studied conclusion was that Oumuamua is an unusual but natural asteroid-like body of extrasolar origin, the first such object ever discovered. However its star of origin is not known and it can’t be studied further because it travelled away so rapidly. Its speed after exiting the solar system indicates it will take about 10,000 years to travel one light year, according to NASA reports.
Considerable excitement therefore greeted the new extrasolar object now in our skies, discovered in Aug 2019 by Gennady Borisov, a Russian telescope maker and amateur astronomer who has discovered several comets. Comet 2I/Borisov apparently does exhibit a coma and faint broad tail with gas, dust, and nucleus similar to solar system comets. It is reportedly faint at present (magnitude ~15) making it challenging though maybe not impossible to observe with a telescope here through the end of the year. The perihelion date (closest approach to the sun) is Dec 8 when it will pass within 2 AU of the sun. Its unprecedented high angle of approach and very high velocity mean that it won’t be captured by the sun. This means it came from “out there” and it will leave the solar system. This makes 2I/Borisov only the second interstellar visitor to be discovered in the entire human history of astronomy.
While extrasolar comets have been anticipated, their detection is unprecedented, and they are undoubtedly rare events on human time scales. The recent advances in technology have enabled these discoveries, analogous to extrasolar planets which were long thought to be out there, but not detectable until the breakthroughs in astro-technologies and orbiting satellite observatories.
Skynet remote imaging for AAAP members
A good way to get going in astrophotography and learn more directly how modern astronomy is being done is to check out Skynet. This is being offered as a unique benefit of AAAP membership not provided by other astronomy clubs in the region. Skynet is the brainchild of Dr Dan Reichart of the Physics and Astronomy Dept at UNC-Chapel Hill. In June we renewed the contract with UNC-Chapel Hill for another two years. Skynet’s internet-based queue scheduling software program runs on UNC computers to connect a system of observatories around the globe established for remote imaging. The Skynet Robotic Telescope Network comprises more than a dozen telescopes in Chile, Australia, Italy, Canada, and the US. Each telescope is set up with robotic tracking mount, CCD camera, and filters for remote image acquisition. Tutorial videos are available when you obtain a user account.
For beginning or seasoned observers, Skynet’s easy-to-use interface taps into an extensive hardware network and large database of celestial objects from the Messier and NGC deep sky catalogs. It includes a basic image processing program “Afterglow” that runs on the server so you don’t need any special software on your computer. You can download the data files and process the images at home on your own PC. Skynet is intended as an introduction to modern astronomy and astrophotography, and is used by science students at UNC and other institutions. Interested AAAP members are urged to take advantage of the club’s investment in Skynet access. Send me an e-mail note to get your user account at no cost to you as an individual. Email email@example.com