|Home | Stars | Habitability | Life ||
NASA -- larger image
Lacaille 9352 is a dim red dwarf star, like Gliese
623 A (M2.5V) and B (M5.8Ve) at lower right.
(See a 2MASS Survey image of Lacaille 9352
from the NASA Star and Exoplanet Database.)
Lacaille 9352 is located about 10.7 light-years (ly) from our Sun, Sol, in the southwestern edge (23:05:42.04-35:51:11.06, ICRS 2000.0) of Constellation Piscis Australis (or Austrinus), the Southern Fish, near Constellation Grus, the Crane -- southeast of Beta Piscis Australis/Austrini and southwest of Gamma and Delta Piscis Australis/Austrini. It was listed by the Abbé [Abbot] Nicholas Louis de La Caille (1713-1762), who had the great honor of naming 15 of the 88 constellations by becoming the first astronomer to systematically observe the entire night sky, in his posthumously published 1763 catalogue of 9,766 stars that was compiled from 1750 to 1754 by studying the stars of the southern hemisphere at the Cape of Good Hope, the southernmost point of Africa, with just an half-inch (8x) refractor. The star is too faint to be seen with the naked eye.
Due to Lacaille 9352's proximity to Sol, the star has been an object of high interest among astronomers. It has been selected as a "Tier 1" target star for NASA's optical Space Interferometry Mission (SIM) to detect a planet as small as three Earth-masses within two AUs of its host star (and so some summary system information and may still be available from the SIM Teams). The SIM project manager announced on November 8, 2010, however, that the mission was indefinitely postponed due to withdrawal of NASA funding.
Medialab, © ESA
Larger illustration of
the Darwin Mission.
Astronomers have identified
Lacaille 9352 as a prime target
for NASA's optical SIM and the
ESA's infrared Darwin missions,
now both indefintely postponed.
This spectral and luminosity type of this cool and dim, main sequence red dwarf may be around M1.5 Ve (RECONS), but it has been classed as orange as M0.5 (Demory et al, 2009, Table 4; and Hawley et al, 1996). Lacaille 9352 may have 50 to 58 of Sol's mass (Demory et al, 2009, Table 4; RECONS; and NASA Star and Exoplanet Database, interpolation table of Henry and McCarthy, 1993), less than half (43 to 46 percent) of its diameter (Demory et al, 2009, Table 4; and NASA Star and Exoplanet Database, derived from the power law formula of Kenneth R. Lang, 1980), 1.1 percent of its visual luminosity and 3.5 percent of its bolometric luminosity (NASA Star and Exoplanet Database, derived from the exponential formula of Kenneth R. Lang, 1980), and only about one tenth to 60 percent of Sol's abundance of elements heavier than hydrogen ("metallicity") (Demory et al, 2009, Table 4). It has been designated with the New Suspected Variable number NSV 14420. Some alternative names and useful catalogue numbers for this star are: Gl 887, Hip 114046, HD 217987, CD-36 15693, CP(D)-36 9694, SAO 214301, LHS 70, LPM 849, LTT 9348, LFT 1758, and Cordoba 31353.
Accounting for infrared light, the distance from Lacaile 9352 where an Earth-type planet would be comfortable warm enough to have liquid water is about 0.22 AU (SIM summary data). According to alternative calculations performed for the NASA Star and Exoplanet Database, their estimate of the HZ would be centered around 0.270 AU, with inner edge of Lacaille 9352's habitable zone slightly farther out at around 0.183 AU from the star, while the outer edge lies even farther out at around 0.358 AU. At such close orbital distances, the orbital period would be around 55 days, and the rotation of the planet may become tidally locked with the star so that one side would have perpetual daylight while the other would be in darkness. Moreover, the light emitted by red dwarfs may be too red in color for Earth-type plant life to perform photosynthesis efficiently.
Hunt for Substellar Companions
A recent search for faint companions using the Hubble Space Telescope found no supporting evidence for a large Jupiter or brown dwarf sized object (Schroeder et al, 2000).
The following star systems are located within 10 ly of Lacaille 9352.
|Star System||Spectra &|
|EZ Aquarii 3||M5-5.5 Ve |
|Epsilon Indi||K3-5 Ve||4.7|
|Lacaille 8760||K7-M2 Ve||4.9|
|Gliese 876 / Ross 780||M3.5 V||6.7|
|Luyten 726-8||M5.6 Ve||6.7|
|YZ Ceti||M4.5 Ve||6.8|
|CD-49 13515 / Gl 832||M1.5 V||7.3|
|Tau Ceti||G8 Vp||7.9|
|G 158-27||M5.5 V||8.5|
|L 722-22 AB||M4 V |
|Ross 154||M3.5-6 Ve||9.6|
|LHS 1565||M5.5 V||9.8|
Up-to-date technical summaries on this star can be found at: the Astronomiches Rechen-Institut at Heidelberg's ARICNS, the NASA Star and Exoplanet Database, the Research Consortium on Nearby Stars (RECONS) list of the 100 Nearest Star Systems, and the SIMBAD Astronomical Database. Additional information may be available at Roger Wilcox's Internet Stellar Database.
Also known as Piscis Australis, Piscis Austrinus is supposed to represent a fish lying on its back, drinking in the waters pouring from the jars of Aquarius. Known since ancient times, the constellation may have been the original Constellation Pisces, referring to the Assyrian Fish God Dagon and the Babylonian God Oannes. In Arabic, it is the Constellation Al Hut al Janubiyy, the Large Southern Fish. For more information on stars and other objects in this Constellation, go to Christine Kronberg's Pisces Austrinus. For an illustration, see David Haworth's Piscis Austrinus.
For more information about stars including spectral and luminosity class codes, go to ChView's webpage on The Stars of the Milky Way.
© 1998-2011 Sol Company. All Rights Reserved.