Sky Object of the Month – May 2017

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Sky Object of the Month – May 2017

(Courtesy LVAS Observer’s Challenge*)

M98 (NGC 4192 – Galaxy in Coma Berenices (Mag. 10.1; Size 9.8’ X 2.8’)

            Spring is galaxy season, with the Virgo Galaxy Cluster well-placed in the evening sky after sunset. The cluster is home to over a dozen Messier objects, including this month’s LVAS Challenge, the nearly edge-on spiral M98 (NGC 41920). At magnitude 10.1, M 98 is one of the faintest Messier objects, but it’s relatively easy to locate as it lies just a little over 6o east of Regulus and 1/2o west of 5th magnitude 6 Comae.

            As faint as it is, M98 can be seen with a small-aperture scope. I first saw M98 on April 2, 1978, using a 3-inch f/10 reflector and a magnifying power of 30X. The galaxy required averted vision and a chart (an Astro Card) that pinpointed its precise location. I reobserved M98 on the evening of April 12, 2015, this time with a 4.5-inch f/8 reflector and16mm Nagler eyepiece that yielded 57X and a 1.4o field. M98 was extremely faint, once again visible only because I knew exactly where to look. Despite the dimness, its elongated form was unmistakable.

            Along with nearby M99 and M100, M98 was discovered by Messier’s comet-hunting contemporary Pierre Méchain on the evening of March 15, 1781. It lies approximately 60 million light years away and, unlike the vast majority of galaxies, is actually approaching the earth at a speed of about 80 miles/second. This “blue shift” behavior is due to its motion within the Virgo Galaxy Cluster.

 

Glenn Chaple for the LVAS

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freestarcharts.co

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Mario Motta M.D.

 

 

 

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