"The HARPS search for southern extra-solar planets XI. Super-Earths (5 & 8 M_Earth) in a 3-planet system"
S. Udry, X. Bonfils, X. Delfosse, T. Forveille, M. Mayor, C. Perrier, F. Bouchy, C. Lovis, F. Pepe, D. Queloz, J.-L. Bertaux, 2007
A&A 469, L43 (ADS)

"The HARPS search for southern extra-solar planets. VI. A Neptune-mass planet around the nearby M dwarf Gl 581"
X. Bonfils, T. Forveille, X. Delfosse, S. Udry, M. Mayor, C. Perrier, F. Bouchy, F. Pepe, D. Queloz, J.-L. Bertaux, 2005
A&A 443, L15 (ADS)

Gl 581 b announced during the Colloquium "The Tenth Anniversary of 51 Peg b" at Observatoire de Haute-Provence, August the 22nd 2005.

Gl 581 c and d announced on April the 25th 2007 in ESO-PR 22/07

 

Larger image

HARPS Phase-folded orbits of the low-mass planets orbiting Gl 581.

Orbital solution (free eccentricity case from Udry et al. 2007):

Object	Period (days)	T0 (JD - 2 400 000)	Eccentricity	V (km/s)	Omega (deg)	K1 (m/s)	m2sini (M_Earth)	a (AU)	N	Residuals (m/s)
Gl 581 b	5.3683 +/- 0.0003	52998.76 +/- 0.62	0.02 +/- 0.01	-9.2116 +/- 0.0002	273 +/- 42	12.48 +/- 0.21	15.7	0.041	50	1.23
Gl 581 c	12.932 +/- 0.007	52993.38 +/- 0.96	0.16 +/- 0.07	-	267 +/- 24	3.03 +/- 0.17	5.03	0.073	"	"
Gl 581 d	83.6 +/- 0.7	52936.90 +/- 9.20	0.20 +/- 0.10	-	295 +/- 28	2.52 +/- 0.17	7.7	0.25	"	"

Stellar properties:

Parameter	Value	Reference
Sp. Type	M3	Hawley et al. 1997
pi (mas)	159.52	Hipparcos
d (pc)	6.26	Hipparcos
m_v (mag)	10.55 +/- 0.01	Mermilliod et al. 1997
m_k (mag)	5.85 +/- 0.03	Leggett 1992
B-V (mag)	1.60	Mermilliod et al. 1997
T_eff (K)	-	-
M_v (mag)	11.56 +/- 0.03	-
M_k (mag)	6.86 +/- 0.04	-
L (L_sol)	0.013	Bonfils et al. 2005
log(g) (CGS)	-	-
M_1 (M_sol)	0.31 +/- 0.02	Bonfils et al. 2005
log(R'HK)	-	-
P_rot (d)	-	-
Vsini (km/s)	<2.1	Bonfils et al. 2005
Age (Gyr)	>2	Bonfils et al. 2005
[Fe/H]	-0.25	Bonfils et al. 2005

Links:

Extrasolar planet page

Planet Search and Stellar Kinematics group page

Geneva observatory

University of Geneva

 

stephane.udry@obs.unige.ch