TWO JUPITER-MASS PLANETS ORBITING HD 154672 AND HD 205739

The Jupiter Twin HD 154345b

We announce the discovery of a twin of Jupiter orbiting the slightly metalpoor ([Fe/H] = −0.1) nearby (d= 18 pc) G8 dwarf HD 154345. This planet has a minimum mass of 0.95 MJup and a 9.2 year, circular orbit with radius 4.2 AU. There is currently little or no evidence for other planets in the system, but smaller or exterior planets cannot yet be ruled out. We also detect a ∼ 9-year activity cyc...

A new Neptune - mass planet orbiting HD 219828 ⋆

Two years ago a new benchmark for the planetary survey was set with the discoveries of three extrasolar planets with masses below 20M⊕. In particular, the serendipitous discovery of the 14M⊕ planet around µ Ara found with HARPS with a semi-amplitude of only 4 m s −1 put in evidence the tremendous potential of HARPS for the search of this class of very low-mass planets. Aiming to discovering new...

Two Earth - sized planets orbiting

Refined Parameters of the Planet Orbiting Hd 189733

We report on the BVRI multi-band follow-up photometry of the transiting extrasolar planet HD 189733b. We revise the transit parameters and find planetary radius R P = 1.154 ± 0.032R J and inclination i P = 85.79 ± 0.24 •. The new density (∼ 1g cm −3) is significantly higher than the former estimate (∼ 0.75g cm −3); this shows that from the current sample of 9 transiting planets, only HD 209458 ...

A Flared, Orbiting, Dusty Disk around Hd 233517

We find that the infrared excess around HD 233517, a first-ascent red giant, can be explained naturally if the star possesses an orbiting, flared, dusty disk. We estimate that the outer radius of this disk is 45 AU and the total mass within the disk is 0.01M . We speculate that this disk is the result of the engulfment of a lowmass companion star that occurred when HD 233517 became a red giant....