Tag Archives: December

Aries (The ram)

Constellation AriesAries is the zodiacal constellation named after the ram.  In ancient times, this constellation represented the golden fleece that was stolen by Jason and the Argonauts. It is one of the 48 constellations cataloged by 2nd century astronomer Ptolemy that remain among the 88 modern constellations. It is located on the ecliptic between Pisces and Taurus, and just south of Triangulum. It is highest in the sky at darkness and can be best seen in December.  Its brightest star is Hamal (Alpha Arietis), and most of this constellation’s stars can be picked out in most light polluted urban skies, but the constellation bears little resemblance to a ram.
http://en.wikipedia.org/wiki/Aries_(constellation)

IAU Aries chart, IAU and Sky & Telescope magazine (Roger Sinnott & Rick Fienberg), June 4, 2011.
IAU Aries chart, IAU and Sky & Telescope magazine (Roger Sinnott & Rick Fienberg), June 4, 2011.

© James R. Johnson, 2014
jim@jrjohnson.net

Triangulum (The triangle)

Triangulum, AndromedaThis small northern constellation presents as well-formed triangle of three stars. It was one of the 48 constellations cataloged by 2nd century astronomer Ptolemy that remain among the 88 modern constellations. It is not bright enough to jump out at the observer, but can be seen in all but the most light-polluted skies. Look for it high overhead between Perseus, Andromeda, and Pisces in December. M33, the Triangulum Galaxy, is the brightest and most notable deep sky object in this constellation.
http://en.wikipedia.org/wiki/Triangulum

610px-Triangulum_IAU.svg
IAU Triangulum chart, IAU and Sky & Telescope magazine (Roger Sinnott and Rick Fienberg), June 5, 2011

© James R. Johnson, 2014
jim@jrjohnson.net

Phoenix (The mythical Phoenix)

Constellation PhoenixMythical Phoenix is very low and dim southern constellation that is challenging to locate from northern latitudes. Find it by drawing a line southward from Pisces through Cetus and Sculptor. Because it is located so far south, it is only visible at its highest nightfall ascension in December, and perhaps its brightest star, Ankaa (Alpha Phoenicis) will be the only star visible through the haze on the horizon. Two recently-discovered galaxy clusters, Phoenix and El Gordo, are among the largest objects in the visible universe.
http://en.wikipedia.org/wiki/Phoenix_(constellation)

IAU Phoenix chart, IAU and Sky Telescope magazine, Roger Sinnott and Rick Fienberg, June 5, 2011.
IAU Phoenix chart, IAU and Sky & Telescope magazine (Roger Sinnott and Rick Fienberg), June 5, 2011.

© James R. Johnson, 2014.
jim@jrjohnson.net

Sculptor (The sculptor)

The Sculptor is a southern constellation of dim stars that does not rise very high in the sky. It is located south of a point half way between Aquarius and Cetus, and can only be seen from October through January, reaching its highest nightfall ascension in early December. The most notable characteristic of this constellation is that it contains the southern pole of the Milky Way Galaxy. The implication of this is that an observer is looking out of the galactic plane, instead of through its long axis as when observing the Milky Way. This explains why there are fewer stars in this region of the sky.
http://en.wikipedia.org/wiki/Sculptor_(constellation)

IAU Sculptor chart, IAU and Sky & Telescope magazine (Roger Sinnott and Rick Fienberg), June 5, 2011.
IAU Sculptor chart, IAU and Sky & Telescope magazine (Roger Sinnott and Rick Fienberg), June 5, 2011.

© James R. Johnson, 2014.
jim@jrjohnson.net

Cetus (A sea monster in Greek mythology)

CetusCetus, the Greek mythological sea monster, is a large southern constellation on the celestial equator, and one of the 48 constellations cataloged by 2nd century astronomer Ptolemy. It is accompanied by other water constellations – Pisces, Aquarius and Eridanus. Its head is nestled among three zodiacal constellations: Taurus, Aries and Pisces. Its body is south (below) Pisces, and is flanked by Aquarius and Eridanus. Cetus’ close proximity to the ecliptic means that the Moon, planets and asteroids occasionally pass through this constellation. Cetus is placed highest in the sky at nightfall in December.

Cetus is home to one Messier object, M77, a striking face-on spiral galaxy. Among Cetus’ stars is an unusual variable star, the disappearing  one, or Mira (Omicron Ceti). This star’s high variability from 3rd magnitude to 10th magnitude means that it disappears from view when it dips below 5th or 6th magnitude. Cetus’ brightest star Menkar (Alpha Ceti) marks the sea monster’s nose.
http://en.wikipedia.org/wiki/Cetus

IAU Cetus chart, Sky & Telescope magazine (Roger Sinnott and Rick Fienberg), June 5, 2011.
IAU Cetus chart, Sky & Telescope magazine (Roger Sinnott and Rick Fienberg), June 5, 2011.

© James R. Johnson, 2014.
jim@jrjohnson.net

Pisces (The fishes)

Constellation PiscesThis zodiacal constellation is a rather dim grouping of stars that are strung out low across the southern sky, just below the Great Square of Pegasus. Pisces is one of the 48 constellations cataloged by the 2nd century astronomer Ptolemy that remain among the 88 modern constellations. It is highest in the sky and best observed at nightfall in December. The intersection of the ecliptic and the celestial equator lie within this constellation. There are two such intersections that mark the two equinoxes. At the intersection in Pisces, the Sun is moving from south to north, so this is the point of the Vernal (spring) Equinox. This constellation is home to just one Messier object, M74.
http://en.wikipedia.org/wiki/Pisces_(constellation)

IAU Pisces chart, IAU and Sky & Telescope magazine (Roger Sinnott & Rick Fienberg), June 5, 2011

© James R. Johnson, 2014
jim@jrjohnson.net

Andromeda (Cassiopeia’s daughter)

Andromeda, CassiopeiaAndromeda, the mythological daughter of Cepheus and Cassiopeia, is located near these two constellations and among several other constellations representing the Perseus myth, to include Perseus, Pegasus, and Cetus. It is one of the 48 constellations cataloged by 2nd century astronomer Ptolemy that remain among the 88 modern constellations. It is found directly overhead at the zenith after sunset in December. Although Andromeda is not a very distinct constellation in light-polluted skies, most of its stars can be observed. It’s brightest star, Alpheratz (Alpha Andromeda), is shared with the constellation Pegasus, and marks one corner of the Great Square of Pegasus. Locate this constellation by starting with the north eastern most star of the Great Square of Pegasus, and find the remaining stars flowing north east from there.

The Andromeda Galaxy (M31), M31boboThe Milky Way’s closest galactic neighbor, is found in this constellation. M31 can be found with the unaided eye in the very darkest of dark skies, but can easily be found with a binocular or telescope under most adverse light pollution conditions. M31 and M110 are two of M31’s dwarf companion galaxies that can also be seen in most photographs of M31.
http://en.wikipedia.org/wiki/Andromeda_(constellation)

IAU Andromeda chart, IAU and Sky & Telescope magazine (Roger Sinnott and Rick Fienberg), June 4, 2011.
IAU Andromeda chart, IAU and Sky & Telescope magazine (Roger Sinnott and Rick Fienberg), June 4, 2011.

© James R. Johnson, 2014
jim@jrjohnson.net

Sagittarius (The archer)

Constellation SagittariusSagittarius, the archer, is a zodiacal constellation that is rather easily found because of its distinctive teapot asterism. It is one of the 48 constellations cataloged by the 2nd century astronomer Ptolemy. It is located on the ecliptic between Scorpius and Capricornus. It can also be found by starting at Altair (a Summer Triangle star) and tracing southward along Aquila’s long axis. As is situated on southern most point of the ecliptic, this constellation hangs low in the southern sky, reaching its highest nightfall ascension in August. The Sun’s arrival at the southernmost point of the ecliptic around December 21st marks Winter Solstice and the first day of Winter.

This constellation has the distinction of presenting the foreground stars in the direction of the dense center of the Milky Way galaxy, which is rich in Messier objects. As such, it is worth taking the time to scan this constellation with binoculars or a small telescope. Several well-known nebula can be found in Sagittarius to include the Lagoon Nebula (M8), the Horseshoe Nebula, the Omega Nebula (M17), the Trifid Nebula (M20), and the Small Sagittarius Star Cloud (M24). Other Messier objects include M18, M22, M23, M25, M28, M54, M55, M69, M70 and M75.
http://en.wikipedia.org/wiki/Sagittarius_(constellation)

IAU Sagittarius chart, Sky & Telescope magazine, June 5, 2011.
IAU Sagittarius chart, Sky & Telescope magazine (Roger Sinnott and Rick Fienberg), June 5, 2011.

© James R. Johnson, 2014.
jim@jrjohnson.net

Gemini (The twins)

Constellation GeminiGemini, the twins, is a zodiacal constellation that was also one of the 48 constellations cataloged by 2nd century astronomer Ptolemy that remain among the 88 modern constellations. This constellation located above Orion’s left shoulder, and between Taurus and Cancer on the ecliptic. It is highest in the sky at nightfall in March, and is quickly identified by two rather bright stars of approximately equal brightness, Castor and Pollux, that represent each of the Gemini twins. The ecliptic reaches its northernmost separation from the celestial equator in Gemini, and the Sun’s arrival at this point marks the Summer Solstice.  The annual Geminids is a prominent annual meteor shower that peaks between December 13th and 14th. Only one Messier object, M35, is located in Gemini.
http://en.wikipedia.org/wiki/Gemini_(constellation)

IAU Gemini chart, IAU and Sky & Telescope magazine (Roger Sinnott and Rick Fienberg), June 5, 2011.
IAU Gemini chart, IAU and Sky & Telescope magazine (Roger Sinnott and Rick Fienberg), June 5, 2011.

© James R. Johnson, 2014.
jim@jrjohnson.net