2006/09/09 by Mercedes López‐Morales, Mercedes Lopez-Morales, N. Morrell +3 · 16 citations
Physics and Astronomy · #Astro and Planetary Science #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Epoch (astronomy) #Exoplanet #Light curve #Neptune #Observatory #Photometry (optics) #Physics #Planet #Planetary system #Stars #Stellar, planetary, and galactic studies #Transit (satellite) #astro-ph
paper · pdf · doi:10.1086/508904
published in Publications of the Astronomical Society of the Pacific 118(849), 1506-1509 (Institute of Physics) · 7 pages, 2 figures, 1 table, to appear in PASP
arxiv created 2006/09/09 · openalex publication_date 2006/11/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We have monitored the Neptune‐mass, exoplanet‐hosting M dwarf GJ 581 with the 1 m Swope Telescope at Las Campanas Observatory over two predicted transit epochs. A neutral density filter centered at 550 nm was used during the first epoch, yielding 6.33 hr of continuous light‐curve coverage with an average photometric precision of 1.6 mmag and a cadence of 2.85 minutes. The second epoch was monitored in the B band over 5.85 hr, with an average photometric precision of 1.2 mmag and a 4.28 minute cadence. No transits are apparent on either night, indicating that the orbital inclination is less than 88 1 for all planets with radii larger than 0.38R Nep (=1.48 R ⊕ ). Because planets with the most likely interior compositions will have radii larger than 1.55 R ⊕ , we place an inclination limit of 88 1 for the system. The corresponding minimum mass of the exoplanet GJ 581b remains 0.97 M Nep (=16.6 R ⊕ ).