Volume 472, Number 2, September III 2007
|Page(s)||L13 - L16|
|Published online||30 May 2007|
Letter to the Editor
Detection of transits of the nearby hot Neptune GJ 436 b
Observatoire de Genève, Université de Genève, 1290 Sauverny, Switzerland e-mail: email@example.com
2 Institut d'Astrophysique et de Géophysique, Université de Liège, 4000 Liège, Belgium
3 Observatoire François-Xavier Bagnoud – OFXB, 3961 Saint-Luc, Switzerland
4 School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, Israel
5 Laboratoire d'Astrophysique, École Polytechnique Fédérale de Lausanne (EPFL), Observatoire, 1290 Sauverny, Switzerland
Accepted: 16 May 2007
This Letter reports on the photometric detection of transits of the Neptune-mass planet orbiting the nearby M-dwarf star GJ 436. It is by far the closest, smallest, and least massive transiting planet detected so far. Its mass is slightly larger than Neptune's at . The shape and depth of the transit lightcurves show that it is crossing the host star disc near its limb (impact parameter ) and that the planet size is comparable to that of Uranus and Neptune, km = . Its main constituant is therefore very likely to be water ice. If the current planet structure models are correct, an outer layer of H/He constituting up to ten percent in mass is probably needed on top of the ice to account for the observed radius.
Key words: stars: planetary systems / stars: individual: GJ 436 / techniques: photometric
© ESO, 2007
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.