HD 111232 / CP(D)-67 2079
|Home | Stars | Orbits | Habitability | Life ||
This star is located around 95 light-years (HIPPARCOS Plx=34.63 +/- 0.80) from Sol. It lies near the center (12:48:51.8-68:25:30.5, ICRS 2000.0) of Constellation Musca, the Fly -- east of Alpha Muscae, south of Beta Muscae, northwest of Delta Muscae, northeast of Gamma Muscae. In June 2003, astronomers announced the discovery of a Jupiter-class planet around this Sun-like star (Observatoire de Genève page on HD 111232 -- details below). (See an animation of the planetary and potentially habitable zone orbits of this system, with a table of basic orbital and physical characteristics.)
The star was first designated as CP(D)-67 2079 (as in ChView data files) by the 1900 publication of the third part of the Cape Photographic Durchmusterung or CPD, based on photographic plates taken by David Gill (1843-1914) at the Royal Observatory on the Cape of Good Hope, South Africa, that were analyzed by Jacobus Cornelius Kapteyn (1851-1922). One of the first major photographic surveys of modern astronomy, the CPD was a continuation of older visual surveys descended from a catalogue by Friedrich Wilhelm August Argelander (1799-1875) in 1863 on the position and brightness of 324,198 stars between +90° and -2° declination that were measured over 11 years from Bonn, Germany, made with his assistants Eduard Schönfeld (1828-1891) and Aldalbert Krüger (1832-1896), which became famous as the Bonner Durchmusterung ("Bonn Survey") or BD. A complement to the BD was created with a visual survey of southern stars that was begun in 1892 at the Astronomical Observatory of Cordoba in Argentina under the direction of its second director John M. Thome (1843-1908). Thome died before the completion of this southern sky atlas in 1914, when 578,802 stars from declination -22° to -90° were published as the Cordoba Durchmusterung ("Survey") or CD.
Today, many astronomers refer to this star as HD 111232 in the Henry Draper (1837-82) Catalogue with extension (HDE), a massive photographic stellar spectrum survey carried out by Annie Jump Cannon (1863-1941) and Edward Charles Pickering (1846-1919) from 1911 to 1915 under the sponsorship of a memorial fund created by Henry's wife, Anna Mary Palmer. (More discussion on star names and catalogue numbers is available from Alan MacRobert at Sky and Telescope and from Professor James B. Kaler's Star Names.)
HD 111232 is a yellow-orange main sequence dwarf star of spectral and luminosity type G5 V, but it has been classed as orange as a G8. The star probably has around 90 percent of Sol's mass, a slightly smaller diameter, and 68 percent of its luminosity. It appears to be only around 44 percent as enriched as Sol with elements heavier than hydrogen ("metallicity"), based on its abundance of iron. Middle-aged like Sol, it may be around 5.17 billion years old (Donahue, 1993?). Useful catalogue numbers and designations for the star include: Hip 62534, HD 111232, and CP(D)-67 2079.
In June 2003, a team of astronomers (including Dominique Naef, Francisco Pepe, Michel Mayor, Nuno C. Santos, Didier Queloz, and Stephane Udry) announced the discovery of a Jupiter-class planet around HR 111232 using radial-velocity methods (Observatoire de Genève page on HD 111232). Planet "b" has at least 7.8 times Jupiter's mass. It moves around HD 111232 at an average distance of 2.07 AUs (a semi-major axis beyond Mars orbital distance) in a highly eccentric orbit (e= 0.25 +/- 0.01) that takes around 1,138 +/- 18 days (3.1 years to complete. The planet is probably similar to Jupiter in size.
The orbit of an Earth-like planet (with liquid water) around HD 111232 may be centered around 0.82 AU -- between the orbital distances of Venus and Earth -- with an orbital period of around 290 days (or 0.8 years). However, the development of an Earth-like planet in this zone could have been disrupted by the eccentric orbit of planet b. Astronomers would find it very difficult to detect an Earth-type planet in the water zone of this star using present methods. (See an animation of the planetary and potentially habitable zone orbits of this system, with a table of basic orbital and physical characteristics.)
The following table includes all star systems known to be located within 10 light-years (ly), plus more bright stars within 10 to 20 ly, of HD 111232.
|Star System||Spectra &|
|CP-67 2198||M0 V||3.7|
|Delta Muscae AB||K2 III |
|* plus bright stars *||. . .|
|HR 5279||G1-3 V-IV||15|
|HR 4413 AB||F7 V |
|HR 5443||F7-8 V||16|
|Gacrux 2?||M3.5 III |
Up-to-date technical summaries on this star can be found at: Jean Schneiders's Extrasolar Planets Encyclopaedia; the HIPPARCOS Catalogue using the VizieR Search Service mirrored from the Centre de Données astronomiques de Strasbourg (CDS); NASA's ADS Abstract Service for the Astrophysics Data System; and the SIMBAD Astronomical Database mirrored from CDS, which may require an account to access.
Musca is a southern hemisphere constellation created by Dutch navigators Pieter Dirkszoon Keyser and Frederick de Houtman, who charted the southern skies from 1595 to 1597. Johann Bayer (1572-1625) designated the constellation as Apis, "The Bee" -- similar to the constellation Apus -- in a collection of new constellations for his 1603 book Uranometria, but this designation did not persist. Edmund Halley (1656-1742) later called it Musca Apis, but the Abbé [Abbot] Nicholas Louis de La Caille (1713-1762) subsequently called it Musca Australis, which has since been shortened to Musca. Indeed, the constellation's full name is actually Musca Australis vel Indica, The Southern or Indian Fly, but the longer designation is no longer needed to distinguish it from the now obsolete Musca Borealis, the Northern Fly. For more information on stars and other objects in Constellation Musca and an illustration, go to Christine Kronberg's Musca. Another illustration is available at David Haworth's Musca.
For more information about stars including spectral and luminosity class codes, go to ChView's webpage on The Stars of the Milky Way.
© 2003 Sol Company. All Rights Reserved.