Sky Object of the Month – November 2017

Sky Object of the Month – November 2017

(Courtesy LVAS Observer’s Challenge*)

NGC 772 – Spiral Galaxy in Aries (Mag. 10.3; Size 7.2’ X 4.3’)

 

            The only times I’ve ever made a telescopic foray into Aries have been to admire its beautiful double star Mesarthim (gamma [g] Arietis). This striking pair of white magnitude 4.8 twins gleams like the headlights of some interstellar automobile or perhaps the eyes of a celestial cat. From now on, though, I’ll take a moment to redirect my scope 1½ degrees eastward to take in this month’s LVAS Observer’s Challenge, the galaxy NGC 772. A unique feature of this spiral is a long arm extending westward from the nucleus. Stephen James O’Meara likens its appearance to that of an emerging springtime fern, hence his nick-name the “Fiddlehead Galaxy.” The stretched-out arm is likely a result of a tidal interaction with the nearby elliptical galaxy NGC 770 (refer to the Mario Motta and Canada-France-Hawaii Telescope/Coelum images).

            There are several challenges to consider when tackling NGC 772. What is the smallest aperture telescope with which it can be glimpsed? O’Meara states that it’s as bright as some of the fainter Messier objects. Are you able to discern any structure – the long spiral arm in particular? Can you pick out 12th magnitude NGC 770?

            NGC 772 was first observed by William Herschel on November 29, 1785. At a distance of 106 million light years, it’s twice as large as the Milky Way.

           

                                                                                          Glenn Chaple for the LVAS

 

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NGC 772 (middle) and NGC 770 (top center)  Mario Motta MD

 

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Canada-France-Hawaii Telescope/Coelum

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Finder chart for NGC 772 (www.astrosurf.com)

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