TAAS Monthly Observing Challenge December 2015

Deep Sky Object

NGC 772 (GX) ra: 01h 59m 20.1s dec: +19° 00’ 26” Magnitude (visual) = 10.3 Size = 7.2’ x 4.3’ Position angle = 130°

Description: NGC 772 (also known as Arp 78) is an unbarred spiral approximately 130 million light- away in the Aries. Around 200,000 light years in diameter, NGC 772 is twice the size of the Galaxy, and is surrounded by several satellite – including the dwarf elliptical, NGC 770 – whose tidal forces on the larger galaxy have likely caused the emergence of a single elongated outer spiral arm that is much more developed than the others arms. Halton Arp includes NGC 772 in his Atlas of Peculiar Galaxies as Arp 78, where it is described as a " with a small high- companion".

Two supernovae (SN 2003 hl & SN 2003 iq) have been observed in NGC 772.

Source: https://www.wikipedia.org/wiki/NGC_772

AL: Herschel 400

Challenge Object

NGC 2371 / 2372 (PN) Gemini ra: 07h 25m 34.8s dec: +29° 29’ 22” Magnitude (visual) = 11.2 Size = 62”

Description: NGC 2371-2 is a dual lobed planetary nebula located in the constellation Gemini. Visually, it appears like it could be two separate objects; therefore, two entries were given to the planetary nebula by William Herschel in the "", so it may be referred to as NGC 2371, NGC 2372, or variations on this name.

Source: https://www.wikipedia.org/wiki/NGC_2371-2

AL: Herschel 400, Planetary Nebula

Binocular Object

NGC 1807 (OC) ra: 05h 10m 46.0s dec: +16° 31’ 00” Magnitude (visual) = 7.0 Size = 12’

Description: NGC 1807 is an at the border of the Taurus and near the open cluster NGC 1817. Uranometria 2000.0 Deep Sky Field Guide describes NGC 1807 as “Few ; moderate brightness range; slight central concentration; detached. Probably not a cluster.”

Source: https://www.wikipedia.org/wiki/NGC_1807

AL: Deep Sky Binocular

Double

Lambda Orionis (DS) Orion ra: 05h 35m 08.28s dec: +09° 56’ 02.96” Magnitudes (visual) = 3.5, 5.5 Separation = 4” Position angle = 43° Distance = approximately 1100 light years

Description: A binary star in the constellation Orion consisting of a hot (35,000 K) and luminous (65,000 L) O star, of about 25 solar masses located 4” away from a B star (25,000 K, 5,500 L). Meissa (also known as Hatya) is best known for a huge surrounding ring of gas, called Sh2-264 or the Meissa ring, an astonishing 150 light years across that is ionized by the star. Sh2-264 is itself set within an even larger ring of interstellar dust and molecules. These structures may be composed of material left over from the formation of Meissa that has been compressed by the action of the O star. Alternatively, it’s possible they were created from the blast of another star that exploded in the neighborhood of Meissa a few million years ago.

Source: http://www.daviddarling.info/encyclopedia/M/Meissa.html

AL: