by Rex Parker, PhD, Director

Upcoming AAAP Events. Over its five decades our organization has approached amateur astronomy by combining great science presentations by the pros, hands-on telescopic observation, and science advocacy and outreach. To keep the good energy flowing I’d like to invite members to take part and help organize several projects and activities. If you’d like to help please send me a message at director@princetonastronomy.org. Upcoming events being planned include:

• May 16: Members-only special night at Washington Crossing Observatory.
• June 19-20: Observing weekend at the renowned astronomy dark sky site, Cherry Springs State Park in northern PA. Arrive Friday afternoon before dark and depart Sunday morning.
• Date pending: Field trip to the US Naval Observatory in D.C.
• Date pending: Easy road trip to see the famed Bell Labs Horn Antenna, Holmdel NJ, site of first discovery of cosmic microwave background radiation.
• Sept 11-13: AAAP hosts Jersey Starquest, an observing weekend at a dark sky site with accommodations at Camp Hope near Jenny Jump State Forest in northern NJ.

Recently we embarked on a project to bring video imaging technology to the Observatory, and plans include opportunities for members to learn astrophotography techniques. Video astronomy (Mallincam) is a first essential step towards advanced imaging technologies, and is intended to help break through some of the difficult problems of observing and sharing interesting deep sky objects to members and the public under our light polluted skies. Due to the substantial equipment upgrade project at Washington Crossing Observatory, the observatory will not be open for public events during the month of April this season. Assuming that the equipment is ready by end of April, we plan to open in May for member and public activities.

Planning for new slate of officers. As provided in our by-laws, I have appointed Michael Wright as Chair of the Nominating Committee to assemble a slate of candidates for the 2015-16 Board of Directors. Any member interested in serving on the Board in the role of Director, Assistant Director, Treasurer, Secretary or Program Chair should contact Mike (editors@princetonastronomy.org). Nominations will be announced at the April 14 meeting, and the election will be held at the May 12 meeting.

Spring is Galaxy Season – Part 2. More galaxies are visible in moderately sized telescopes in spring than any other season, led by the dense galaxy clusters in Virgo. If you’ve never seen a galaxy through the eyepiece of a good telescope, this spring will be a great opportunity to try it. The upgrades now underway at AAAP’s Washington Crossing Observatory (new telescopes, new mount, and video astronomy technology) will make it even better. We hope that recent and long-time members will come out to experience the celestial wonders “hands-on” later this spring. Those interested in learning to use the equipment for your own studies and to be a part of our extensive public outreach programs are urged to attend the regular meetings and talk to Observatory co-chairs, Gene Ramsey and Dave & Jennifer Skitt to develop a plan for your training (e-mail: observatory@princetonastronomy.org).

Color in the New Jersey Deep Sky? – Part 2. If you’re considering getting into astrophotography or you are already on the learning curve, you may have wondered about CCD cameras and techniques best suited for our challenging Jersey and Pennsylvania skies. The recent improving weather conditions helped me to make progress in comparing the two major techniques for deep-sky color astrophotography: one-shot color vs. LRGB. I used two different cameras/filters with the same guided tracking telescope in an observatory here in central NJ (see Part 1 in last month’s ST). As noted last month, one-shot color cameras are thought by experts to be unsuited to light-polluted areas. I wanted to test this by comparing the two methods head-to-head. Below are final images of the spiral galaxy M106, created using each method with the cameras indicated. The sky and moon conditions were similar and total exposure time was the same for each: 4.5 hours. The CCD chips of the two cameras have similar pixel sizes but different total pixel number and sensor area, so their fields of view differ. The resulting images were not cropped. While other celestial objects may compare differently, it’s pretty clear that for a target with low surface brightness like a spiral galaxy (magnitude spread out over a wide angular area), the beautiful blues and reds are more intensely captured and better balanced by the LRGB than the one-shot color camera. While that may not be true from a desert mountain site, it does seem so here in central Jersey. More comparisons will be made in the future to see how magnitude, surface brightness, and type of celestial object affects results.

Messier-106, LRGB (ST-10XME camera & CFW8 filter wheel)

Messier-106, one-shot color (SXVR-M25C camera)

Images by Rex Parker, taken in Titusville NJ. Cameras as indicated; Telescope: AGO 12.5-iDK astrograph; Mount: Paramount-MX; Control software: TheSkyX; Data processing: Maxim-DL5, CCD Stack, PS-CS5.