oacnews0907.html

Saturn's retinue in now up to 60 and counting.

Yet another satellite of Saturn has been discovered by the Cassini spacecraft---a roughly 2-kilometer-wide body found in images taken May 30.

Residing 107,700 km from Saturn, the moon orbits between Methone and Pallene, two 4-km-wide moons that were discovered the the craft soon after its arrival in July 2004. The grouping of the three objects suggests that they might be either the left-overs of a collision or a collection of icy objects that failed to coalescew into a larger moon, says Cassini scientist Carl Murray.

Temporarily dubbed S/2007S4, the new object, along with Methone, orbits Saturn in lockstep with a larger satellite, Mimas. It is thought Methone and S2007S4 probably didn't initially have the orbits they do now but fell under the influence of Mimas as gravitational tides exerted by Saturn caused the two small bodies to drift toward the large satellite.

If the Cassini mission is extended beyond its scheduled end in summer 2008, the spacecraft's orbit will take it within 7,300 km of S2007S4 at the end of 2009, enabling the craft to better study the moon's composition and size.

(Credit: SCIENCE NEWS, July 28, 2007)

FUNZIES

CLUB ASTROPHOTO OF THE MONTH

Owl Nebula - Ursa Major

Image Credit - John McSorley

The UNITRON Rides Again

Supplied with new tube rings and a standard dovetail plate, this vintage scope is now available for members to use. Shown below on a Meade mount, the scope is also compatible with most GEM mounts including Celestron, Losmandy, Vixen and Orion.

HISTORY:
Long before Celestron.....long before Meade......in a galaxy far, far away there was UNITRON. Back in the 50s and 60s, these beautifully finished refractors were "state of the art" for their day---and have now become almost legendary collectibles. With superb optics, smooth-chromed mechanics and heavy-duty mounts that could support a battle ship, UNITRON set the standard for excellence. For many, many years Sky-and-Telescope carried full center and full back page ads for various models up to 6" aperture. Parent company United Scientific has chosen in recent decades to concentrate on laboratory equipment such a microscopes, etc. and all but abandoned the Astronomy community, although their website claims some models are still for sale.

SPECS:
102 mm clear aperture air-spaced acromat w/coated optical surfaces
F/15 focal ratio enables larger images and higher mags with longer mm EPs
Lightweight aluminum tube (about 10 pounds)
Originally guaranteed to exceed the Dawes resolution limit for its aperture.
UNIHEX rotary eyepiece selector accepts .96, standard 1.25 and 2" eyepieces.
Exceptionally deep depth-of-focus due to long light cone

APPLICATIONS:
The F/15 focal length is ideal for planetary/lunar viewing and on double stars The "straight through" light path enables clean airy discs on stars and provides beautifully split doubles. Epsilon Lyra is a stunning sight in this scope. Stars do NOT look like seagulls , but pinpoints with clear diffraction rings in the Unitron. The sharp images and incredible resolution of a long-tube refractor are something to be experienced......as well as a part of Astronomy history in the scope itself.

BACKGROUND:
This classic refractor was donated to the Club by deceased member Stan Spindler about two years ago. It could not be used because the original EQ mount lacks a shaft and counterweight. After consultation with Jim Henson at SCOPESTUFF, it was determined that the most economical route to put it back in service would be to obtain tube rings and a universal dovetail plate allowing it to be used on modern GEM mounts. The Club approved a motion to purchase these components at the August meeting.

ASTRONOMY TECHNOLOGY TODAY

Astronomy Technology Today - A new startup magazine for equipment geeks features reviews, specs and images from both users and distributers.
Details on their website: www.astronomytechnologytoday.com

OAKLAND ASTRONOMY CLUB

NEWSLETTER

SEPTEMBER 2007