March 18, 2018

Event: Mars passes the Beehive.

This week offers a two-fer, an easy to spot naked eye conjunction of two very different objects and a difficult to observe occultation. 1st up is a close pairing of the planet Mars and M44, the Beehive Cluster. From the 13th of April until the 20th, both will be grouped in a visual circle less than 2° arc degrees in diameter, an easy target for both camera lens or binocs. Mars will be at closest apparent approach on the evening of the 16th. Both ride high near the zenith in the dusk skies for northern hemisphere viewers, making for an easy photo op. Of course, Mars is a scant 3 odd light minutes away; M44 is at an estimated distance of 577 light years. Also known as Praesepe, the Manger, this cluster in the heart of the constellation Cancer has been known since ancient times. Proper motion studies suggest that this open cluster may share its origins with the V-shaped Hyades in the constellation Taurus; about 1010 members of this group have been identified, including 11 white dwarfs.

Up for a challenge? On the evening of the 15th, the 3 day old crescent Moon will occult the close spectroscopic binary star Mu (µ) Arietis.  The action occurs around 3:00 UT (on the 16th) and favors viewers on the North American west coast. Unfortunately, the event does not occur under the most favorable circumstances; the Moon will be a thin crescent, the star is +6 magnitude, and the entire event will be low in the dusk skies. Still, we’d love to hear from anyone who successfully witnessed this difficult to observe event!

The astro-word for the week is Messier Object. Back in 1771, French astronomer Charles Messier got tired of misidentifying faint little fuzzies he came across in the night sky in his quest for comets and decided to compose a catalog of these objects. The original published list contained 45 objects and Messier later expanded it to 103. The current tally stands at 110, although the list contains a few dubious entries. The catalog was the first list of deep sky objects, and has since spurred countless “Messier Marathons” common in spring. Morphologically, the catalog contains open & globular clusters, planetary nebulae, emission nebulae and galaxies. Of course, Messier had no inkling what these objects truly were when he cataloged them. It’s somewhat odd that such un-comet like objects as M44 and the Pleiades made this list, but say, the Double Cluster on the Perseus-Cassiopeia border did not. And of course, there was a whole menagerie southern sky objects yet to be categorized. That would have to wait for the Herschel dynasty of astronomers, and their expanded New General Catalog!

Astro Event of the Week; November 24th-30th: The Gegenschein.

This weeks’ Astro-challenge to the world (and myself) is to sight that most elusive of astro-beasts, the Gegenschein. Surprisingly, more pictures of Sasquatch on Mars or Paris Hilton in prison exist than of this faint phenomenon. Sometimes called “counter-glow,” this faint glowing patch occurs near the antihelion or spot opposite to the Sun.

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