September 2014
Treasurer's report:
Beginning balance August 1 $1511.33
Less New Hampshire Ins. Co. liability insurance $320.00
Ending balance August 31 $1191.33
October meeting:
Elect officers for coming year
Program otherwise TBD
Astronomy news—Daryl:
Rosetta mission to Comet 67P: Launched March 2004, Rendezvous May 2014, end of mission Dec. 2015. Landing site on 67P in process of being determined.
Supermoons:
July 12, August 10 (even bigger than July), September 8 (a bit smaller than in August)
Sunspots:
Good ones Sept. 9, in the last 4-5 days of a solar flare
Astronomy star party:
Held August 23 E. of high school. Saw Saturn rings and Lagoon Nebula
And that morning, 1 hr before sunrise, waning moon and Jupiter and Venus were in a pretty triangle
Early morning hours now: Good view of Jupiter, Orion, Gemini
John Grismore—presentation on trip to McDonald Observatory and VLA array in New Mexico
The VLA:
On “our” highway 60 (it crosses it!)
Is arranged in 3 arms with 27 antennae total, nine in each arm
Each antenna is independent of the other
Disk diameter of each is 82 ft
Height of each is 94 ft
Weight of each is 230 tons
Antennae can be configured 4 different ways
Maximum aperture is 22 miles
Minimum resolution is .05 arcseconds
Frequency is 74 mHz-60 gHz
VLA was built in 1973-1980 and upgraded in 2010
Train tracks are used to move the antennae.
By 2000, over 10,000 projects had been worked by the VLA by 2200 researchers. The VLA has played a key part in the discovery of ice on the poles of Mercury, micro-quasars in the Milky Way, the first Einstein ring, and precise locations of Gamma ray bursts.
The VLA synthesizes 27 images into one.
McDonald observatory:
Built in the 1930’s
Has a very nice visitor’s center
They encourage night star parties and offer daytime tours of telescopes
If you want to book into a session, plan to do so 6 months to a year ahead
They have a visitor’s amphitheater to view nighttime constellations.
They have 16 inch, 22 inch and 36 inch telescopes
They have a Star Date publication, a radio show and podcast
They have workshops for K-12 teachers
They are now funded by UT; in the 1930s were funded by a Texas banker
They worked with the University of Chicago in the 1930s
They have a dedicated solar telescope
The observatory’s Harlan J Smith telescope’s primary mirror is 107 inches in diameter and weighs 7800 pounds. The telescope tube diameter is 12 ft and length is 32 ft. It weighs overall 16 tons.
The observatory has—
Measured the earth-to-moon distance
Helped develop technology for the Hubble telescope
Helped develop high speed photometry
Helped develop stellar and galactic spectroscopy
The observatory’s Hobby-Eberly site and dome is always 55 degrees above the horizon and is the 5th largest in the world. Has 91 separate hexagonal mirrors and is 30 feet in diameter with full 360-degree azimuth. It has been involved in exoplanet discoveries, supernovae observations, galactic rotations and dark energy research.