Lacerta

Infobox Constellation
name = Lacerta
abbreviation = Lac
genitive = Lacertae
symbology = the Lizard
RA = 22.5
dec= +45
areatotal = 201
arearank = 68th
numbermainstars = 5
numberbfstars = 17
numberstarsplanets = 1
numberbrightstars = 0
numbernearbystars = 1
brighteststarname = α Lacertae
starmagnitude = 3.8
neareststarname = EV Lacertae
stardistance = 16.5
numbermessierobjects = 0
meteorshowers =
bordering = Andromeda
Cassiopeia
Cepheus
Cygnus
Pegasus
latmax = 90
latmin = 90
month = October
notes=:"For the biological genus of lizards, see Lacerta (genus)."Lacerta (pronEng|ləˈsɝtə, _la. lizard), is one of the 88 official constellations acknowledged by the International Astronomical Union. It is not among Ptolemy's 48 ancient constellations. It was created ca. 1687 by the astronomer Johannes Hevelius. It does not contain any particularly bright stars, no Messier object, no galaxy brighter than 14.5m, no globular clusters nor does it contain a named star. Correspondingly, it is rather difficult to find. The northern part lies on the Milky Way. Lacerta is located between Cygnus, Cassiopeia and Andromeda on the northern celestial sphere. It has been likened to Cassiopeia because of its similar "W" shape. As such it is sometimes referred to as 'Little Cassiopeia'.

Notable features

*α Lac: this main sequence star of spectral type A1 V has an apparent magnitude of merely 3.77m. There are no other stars brighter than fourth magnitude. α Lac is an optical double star.
*Roe 47: a multiple star consisting of five components (magnitudes 5.8, 9.8, 10.1, 9.4, 9.8).

Notable deep sky objects

*NGC 7243: an open star cluster of approximately 6.4m.
*BL Lacertae: it was discovered quite early and first thought to be a star and therefore given a variable star designation. However, in reality it is the core of a galaxy. It lent its name to a whole type of celestial objects, the BL Lacertae objects (a subtype of blazar.) The object varies irregularly between magnitudes 14 and 17 over a few days.
*ADS 16402 is a binary star system in Lacerta, around which a planet orbits with some unusual properties. [ [http://www.nytimes.com/2006/09/15/science/space/15planet.html?ref=spaceandcosmos Puzzling Puffy Planet, Less Dense Than Cork, Is Discovered - New York Times ] ] The Jupiter-sized planet exhibits an unexpectedly low density, about the same as cork. This planet is dubbed HAT P-1.

Mythology

Being a modern constellation there is very little mythology surrounding Lacerta.

At about the same time as Johannes Hevelius adopted the name "Lacerta", other names were proposed for this part of the sky, among them "Sceptrum et Manus Iustitiae" (= Scepter and the hand of Justice) and "Frederick's Honors", but Lacerta was finally chosen as the official constellation for this region.

The same constellation was used by the Chumash as "Lizard" and is included in multiple stories. This constellation was supposed as one of many constellations encountered as one went to the Land-of-the-Dead.

In modern fiction, the constellation plays a notable role in Greg Egan's novel Diaspora, where a collision between a pair of hypothetical neutron stars in the constellation results in a gamma ray burst which wipes out biological life on earth.

Citations

References

* Ian Ridpath and Wil Tirion (2007). "Stars and Planets Guide", Collins, London. ISBN 978-0007251209. Princeton University Press, Princeton. ISBN 978-0691135564.

External links

* [http://www.allthesky.com/constellations/lacerta/ The Deep Photographic Guide to the Constellations: Lacerta]
* [http://www.ianridpath.com/startales/lacerta.htm Star Tales – Lacerta]
*Weasner's Mighty ETX Site, [http://www.weasner.com/etx/ref_guides/lacerta.html "GO TO LACERTA"] (a constellation guide for amateur astronomers)