JPL, CalTech, NASA


Larger illustration


Astronomers have identified HD
10647 as a prime target for the
Terrestrial Planet Finder (TPF),
now planned for launch between
2014 and 2020.

Although more recently designated as q1 Eridani, this star was first designated as CP(D)-54 365 (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 10647, as designated 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. As a relatively bright star in Earth's night sky, HD 10647 is also catalogued as Harvard Revised (HR) 506, a numbering system derived from the 1908 Revised Harvard Photometry catalogue of stars visible to many Humans with the naked eye. The HR system has been preserved through its successor, the Yale Bright Star Catalogue -- revised and expanded through the hard work of E. Dorrit Hoffleit and others. (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.)

The Star

Planet "b"

NASA

Cassini-Huygens Mission
to Saturn and Titan


Larger image.


Planetary candidate "b" may
be a large gas giant like Jupiter
(shown here with Europa).

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 10647 using radial-velocity methods (Observatoire de Genève page on HD 10647). Planet "b" is now thought to have at least 91 percent of Jupiter's mass. It moves around HD 10647 at an average distance of 2.1 AUs (a semi-major axis beyond the orbital distance of Mars in the Solar System) in a highly eccentric orbit (e= 0.18 +/- 0.08) that takes around 2.9 years to complete. The planet is probably similar to Jupiter in size.

The orbit of an Earth-like planet (with liquid water) around HD 10647 may be centered around 1.3 AU -- between the orbital distances of Earth and Mars -- with an orbital period around 1.4 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.)

Astronomers are hoping to use NASA's Terrestrial Planet Finder (TPF) and the ESA's Darwin planned groups of observatories to search for a rocky inner planet in the so-called "habitable zone" (HZ) around HD 10647. As currently planned, the TPF will include two complementary observatory groups: a visible-light coronagraph to launch around 2014; and a "formation-flying" infrared interferometer to launch before 2020, while Darwin will launch a flotilla of three mid-infrared telescopes and a fourth communications hub beginning in 2015.