Welcome to the August 2013 STARS Newsletter
The purpose of the newsletter is to communicate information about the club and astronomical events and topics. It is also a place where members can contribute articles, comment on STARS activities and give suggestions for the club and for this newsletter. Email them to me at firstname.lastname@example.org and a copy to the STARS president Alan Rifkin at email@example.com. If you don’t use email, then please talk with me at the next meeting. I’m the guy with a beard, probably sitting in the first row.
No member contributions this month, but I am looking forward to them in the future.
Here is one of Dr. Ethan Siegel’s recent blogs: http://scienceblogs.com/startswithabang/2013/08/01/guest-post-astrochemistry-and-how-the-universe-comes-together/ The blog entries are more technical than the astronomy club articles at the end of our newsletter – but usually have some general interest as well.
Index to this Newsletter:
2) Some Upcoming Events
3) Future Speaker Lists for STARS and SOS (Stars over Springfield)
4-5) Ethan Siegel’s Article: Size Does Matter, But So Does Dark Energy
(Same as last month. Not my fault. It’s only mid-August.)
From our leader on the STARS’ annual picnic:
STARS’ past picnics were at Dick and Edie's Gerry's place but now this year we’ll be having a beach party on Saturday August 24. The cost is $10 per person: while pets are not invited, children, musical instruments, telescopes, bathing suits and towels and BYO are welcome! The club will supply hamburgers, hot dogs, sides, corn on the cob, non-alcoholic drinks, etc. Please RSVP to me (firstname.lastname@example.org), so I know how much food to get. I will start setting up at noon. People are welcome to come and help me set up or just go and jump in the river. Location is Flood Plain Point http://rifkin.com/1-fppt/.
From our star writer, Amanda Jermyn, about the September meeting of STARS:
The next STARS meeting will be Tuesday, September 24th at 7:30pm at the Springfield Science Museum. There will be a slide show and an account of the club’s recent private tour of Harvard University’s Collection of Historical Scientific Instruments. The meeting will also include a report on the summer’s star parties – Stellafane, The Conjunction, Arunah Hill Days and stargazing at the Wilco Music and Arts Festival held at Mass MoCA. Also, Ed Faits will do the Sept. 6 talk for SOS (Stars over Springfield).
BTW: Amanda’s monthly astronomy articles: http://www.reflector.org/amanda/index.php
Speakers for upcoming STARS meetings:
Sept 24 There will be a slide show and an account of the club’s summer activities
Oct. 22: Rich Sanderson - The Maksutov telescope design and its integration in amateur telescope making
Nov. 26: Mission to Mars Panel - 10 minutes per speaker. Moderator: Dave Gallup
1. Mars 101 - Introduction to Mars - Paul Cardone
2. How to get to Mars - orbital mechanics - Alan Rifkin
3. Report on findings of Curiosity Rover - Crystal Mengele
4. NASA 10 minute video of Curiosity landing - Crystal Mengele and Tim Connolly
5. Medical implications of sending people to Mars - David Wexler
Dec. 17: Holiday party. Venue still to be decided.
Jan. 28: Jack Megas and Rich Sanderson will present the planetarium show "Stars around the Campfire," and give a brief introduction to it.
March 25: David Wexler - Cosmology and Space Time
Sep. 6 Ed Faits
Oct. 4 Dave Gallup
Nov. 1 Rich Sanderson - Comets & Meteors, plus Comet ISON
Dec. 6 Paul Cardone
Jan. 3 Ed Faits
Size Does Matter, But So Does Dark Energy
By Dr. Ethan Siegel
Here in our own galactic backyard, the Milky Way contains some 200-400 billion stars, and that's not even the biggest galaxy in our own local group. Andromeda (M31) is even bigger and more massive than we are, made up of around a trillion stars! When you throw in the Triangulum Galaxy (M33), the Large and Small Magellanic Clouds, and the dozens of dwarf galaxies and hundreds of globular clusters gravitationally bound to us and our nearest neighbors, our local group sure does seem impressive.
Yet that's just chicken feed compared to the largest structures in the universe. Giant clusters and superclusters of galaxies, containing thousands of times the mass of our entire local group, can be found omnidirectionally with telescope surveys. Perhaps the two most famous examples are the nearby Virgo Cluster and the somewhat more distant Coma Supercluster, the latter containing more than 3,000 galaxies. There are millions of giant clusters like this in our observable universe, and the gravitational forces at play are absolutely tremendous: there are literally quadrillions of times the mass of our Sun in these systems.
The largest superclusters line up along filaments, forming a great cosmic web of structure with huge intergalactic voids in between the galaxy-rich regions. These galaxy filaments span anywhere from hundreds of millions of light-years all the way up to more than a billion light years in length. The CfA2 Great Wall, the Sloan Great Wall, and most recently, the Huge-LQG (Large Quasar Group) are the largest known ones, with the Huge-LQG -- a group of at least 73 quasars – apparently stretching nearly 4 billion light years in its longest direction: more than 5% of the observable universe! With more mass than a million Milky Way galaxies in there, this structure is a puzzle for cosmology.
You see, with the normal matter, dark matter, and dark energy in our universe, there's an upper limit to the size of gravitationally bound filaments that should form. The Huge-LQG, if real, is more than double the size of that largest predicted structure, and this could cast doubts on the core principle of cosmology: that on the largest scales, the universe is roughly uniform everywhere. But this might not pose a problem at all, thanks to an unlikely culprit: dark energy. Just as the local group is part of the Virgo Supercluster but recedes from it, and the Leo Cluster -- a large member of the Coma Supercluster -- is accelerating away from Coma, it's conceivable that the Huge-LQG isn't a single, bound structure at all, but will eventually be driven apart by dark energy. Either way, we're just a tiny drop in the vast cosmic ocean, on the outskirts of its rich, yet barely fathomable depths.
Digital mosaic of infrared light (courtesy of Spitzer) and visible light (SDSS) of the Coma Cluster, the largest member of the Coma Supercluster. Image credit: NASA / JPL-Caltech / Goddard Space Flight Center / Sloan Digital Sky Survey.
End of the August Newsletter
Copyright © Art Meyer