Gemini (constellation)

Gemini is one of the constellations of the zodiac. It was one of the 48 constellations described by the 2nd century AD astronomer Ptolemy. It is one of the 88 modern constellations today. Its name is Latin for "twins." It is from the twins Castor and Pollux in Greek mythology. Its symbol is (Unicode ♊).

Gemini

Click for larger image
List of stars in Gemini
Abbreviation:	Gem
Genitive:	Geminorum
Symbology:
Right ascension:	7 h
Declination:	+20°
Area:	514 sq. deg. (30th)
Main stars:	8, 17
Bayer/Flamsteed stars:	80
Stars known to have planets:	8
Bright stars:	4
Nearby stars:	4
Brightest star:	Pollux (β Gem) (1.15m)
Nearest star:	Gliese 251 ( ly)
Messier objects:	1
Meteor showers:	Geminids Rho Geminids
Bordering constellations:	Lynx Auriga Taurus Orion Monoceros Canis Minor Cancer
Visible at latitudes between +90° and −60° Best visible at 21:00 (9 p.m.) during the month of February

Location

The constellation Gemini as it can be seen with the naked eye, with added connecting lines.

An animation of the constellation Gemini (center), "the twins", shows two parallel stick figures. Gemini is associated with the myth of Castor and Polydeuces (also known as Pollux). They are all known as the Dioscuri.

Gemini lies between Taurus to the west and Cancer to the east. Auriga and Lynx are to the north. Monoceros and Canis Minor are to the south.

Meteor showers

The Geminids are a meteor shower that can be seen best on December 13–14. People watching it see about 100 meteors per hour at most. It one of the richest meteor showers. The Epsilon Geminids peak between October 18 and October 29. They have only been recently confirmed. They overlap with the Orionids. This makes the Epsilon Geminids hard to see. Epsilon Geminid meteors move faster than Orionids.

Mythology

Gemini as depicted in Urania's Mirror, a set of constellation cards published in London c.1825.

In Babylonian astronomy, the stars Castor and Pollux were known as the Great Twins (MUL.MASH.TAB.BA.GAL.GAL). The Twins were thought of as minor gods. They were called Meshlamtaea and Lugalirra. These names meant 'The One who has arisen from the Underworld' and the 'Mighty King'. Both names can be understood as titles of Nergal, the major Babylonian god of plague and pestilence. He was king of the Underworld.

Visualizations

Diagram of H.A. Rey's alternative way to connect the stars of the constellation Gemini. Twins are shown holding hands.

Castor and Pollux are the brightest stars in Gemini. They are two bright stars that appear very close together forming an o shape.

Astrology

The Sun appears in the constellation Gemini from June 20 to July 20. In tropical astrology, the Sun is in the sign Gemini from May 21 to June 22, and in sidereal astrology, from June 16 to July 15.

Gemini (constellation) Media

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  AFGL 5180 - Through the Clouds.

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  Image of M35 Credit: Atlas Image [or Atlas Image mosaic] obtained as part of the Two Micron All Sky Survey (2MASS), a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation.

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  ESO Very Large Telescope images the Medusa Nebula

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  Medusa nebula (Abell 21), a planetary nebula

References

• Levy, David H. (2005). Deep Sky Objects. Prometheus Books. ISBN 1-59102-361-0.
• H. A. Rey, The Stars — A New Way To See Them. Enlarged World-Wide Edition. Houghton Mifflin, Boston, 1997. ISBN 0-395-24830-2.
• Ridpath, Ian; Tirion, Wil (2001), Stars and Planets Guide, Princeton University Press, ISBN 0-691-08913-2
• Ian Ridpath and Wil Tirion (2007). Stars and Planets Guide, Collins, London. ISBN 978-0-00-725120-9. Princeton University Press, Princeton. ISBN 978-0-691-13556-4.

Other websites

• The Deep Photographic Guide to the Constellations: Gemini
• Astrojan Astronomical Picture Collection Archived 2021-08-31 at the Wayback Machine: The clickable Gemini
• WikiSky: Gemini constellation
• Ian Ridpath's Star Tales: Gemini
• APOD Pictures of Gemini and Deep Sky Objects:

1. A Spring Sky Over Hirsau Abbey
2. The Eskimo Nebula from Hubble
3. The Medusa Nebula
4. Open Star Clusters M35 and NGC 2158
5. NGC 2266: Old Cluster in the NGC

• Constellation Guide: Gemini Constellation