Scheduled time for Public Observing: 9pm – 11pm

Solar System Objects:

The Moon: will be 38° high in the South at 10pm, and 87% illuminated (Waxing Gibbous phase, 11 days old). Tonight is NASA’s International Observe the Moon Night, held annually since 2010. Public observing at Van Vleck is officially registered with NASA as a participating event!

Image (c) Virtual Moon Atlas /

Planets: Mars will be 28° high in the South at 9pm, but getting smaller than previous months at 13 arc seconds in diameter. The polar ice caps will still be visible in a telescope, ongoing dust storm updates can be found here. Neptune will be close by the Moon, and Uranus will be well-placed at 42° altitude in the SE by 10pm.

Deep-Sky Objects:

Double Stars: Gamma Delphinius is a pretty double star, 50° high in the SW at 10pm. 101 light years away, it’s yellow components a easily separated by almost any telescope.

Variable Stars: Are not usually included in public observing, but one exception is worth mentioning tonight, just in time for Halloween. Algol, a.k.a. “The Demon Star” is a naked-eye eclipsing variable that dims to 1/3 of it’s normal brightness every 2 days 20 hours 49 minutes, it reaches minimum brightness at 10:39pm tonight. Taking 5 hours to return to maximum, a check later in the evening or the next day will show an easily visible increase in brightness. A club member would be able to point it out. It’s a chance to see stars revolving around each other in “real time”.

Image courtesy of Starry Night (R) Orion Special Edition, Version: 6.2.3 kcEW, Imaginova (R) Corp.

Nebula and Star Clusters: Several planetary nebulae will be visible tonight.They are shells of glowing gas ejected by solar-type stars at the end of their lives, and are temporary, lasting only about 10,000 years. From West to East (and top to bottom below), are M57 (the Ring Nebula), NGC 6826 (the Blinking Planetary), and NGC 7662 (the Blue Snowball).

Images above were made with an 8″ telescope and video camera, often set up outside the observatory on public nights showing a “live” image.

The globular star cluster M15 is located not far in the sky from the double star Gamma Delphinius.

Man-made Objects:

International Space Station (ISS): The ISS will not be visible during public observing tonight.

Iridium Satellites: These satellites can produce bright flares (brighter than Venus) from their antenna arrays. Any visible flares will be added closer to the observing date, as prediction accuracy improves