and Fabrycky (2010) published a detailed study of the e ects of aliasing on the GJ 581 data set of Mayor09 They concluded that the 67-day period of GJ 581c remains ambiguous, and favored a period of 1 0125 days that produced aliases at both 67 days and 83 days The Gliese 581 system exerts an outsize fascination when compared to many of the
Introduction: Gliese 581 is a M3V red dwarf star approx 2 light years away 2 Radial velocity (RV) measurements suggest that it has a planetary system of four planets (b-e) [1- 3], with the possibility of two additional, unconfirmed planets g and f [4-10] Gliese 581 e is a low mass planet with a minimum mass of 1 9
Gliese 581 a M dw arf with 3 ver y low-mass planets X BonÞls 1 1 Centro deAstronomia e AstroÞsica da Univ ersidade Lisboa, P or tugal 2 Labor atoiredÕAstroph ysique delÕObser v Grenob le, F rance 3 Obser vatoire de Gen v e , Switz er land In the spir itof Ber nard L yot, UC Ber kle y, 2007 S Udr y, X Delf osse , T F or veille , M Ma
cused on the Gl 581 planetary system (also designated GJ 581 in the literature) It was already known to harbor three planets, including two super-Earth planets that straddle its habitable zone: Gl 581 b with a period of 5 37d (Bonfils et al 2005b), Gl 581 c (period 12 9d) and d (period 82d) (Udry et al 2007) Armed with additional HARPS
longer for inner planets e and b Discussion: While the transfer of ejecta between planets is possible in the Gliese 581 system, the poten-tially habitable planets are more biologically isolated Any astrobiological material existing on Gliese 581 d, or one of its hypothetical exomoons, has a small
bar spanning the given distances Note that Gliese c, g and d are located in the HZ of Gliese 581 Because Gliese 581 g is located near the center of this zone and is very likely to be warm enough for there to be liquid water, which is an essential ingredient for life Gliese 581c may be too hot and Gliese 581 d may be too cold
Googling this and checking Wikipedia on Feb 23, 2011: Gliese 581 has a mass of 0 31 that of the Sun and a luminosity of 1 3 that of the Sun Six planets are believed to be orbiting it Gliese 581c has a mass of about 5 times that of Earth, making it very Earth-like
d Gliese 581 e GJ 486 2As of June, 2011, The number of exoplanet candidates found by the transit photometry method is closest to a 250 b 50 c 1250 d 25,000 e 10 3A spectral type G star could be a main sequence star like our own Sun or it could be one of several di⁄erent types of red giant stars
Gliese 581c Source: ESO M dwarf stars M dwarfs are ideal stars to observe in order to find small planets • Low mass - M dwarfs are low mass stars thus it is easier to detect lower mass planets around them • Low luminosity - habital zones for M dwarfs are closer (∼ 0 1 A U ) Gliese 581 Gliese 581 is a M dwarf star
d Gliese 581 e GJ 486 4The star ˇ 3-Orionis is 8 parsecs from our Sun The light from ˇ-Orionis has been traveling for a 2:4 years b 26:4 years c 8:0 years d 0:125 years e 0:4 years 5You hear a 1000Hz tone from a radio that is 20 feet away from you and listen for 4 seconds How many pressure maxima pass by your ear? a 5000 b
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ThesearchforplanetsaroundMdwarfs
Dataanalysis
Gliese581
aMdwarfwith3verylow-massplanets
X.Bonfils
1 1 2 3
ObservatoiredeGenève,Switzerland
InthespiritofBernardLyot,UCBerkley,2007
X.BonfilsGliese581
ThesearchforplanetsaroundMdwarfs
Dataanalysis
Outline
1
ThesearchforplanetsaroundMdwarfs
ThesearchwithHARPS
Sensus
2
Dataanalysis
RVdata
Kepleriananalysis
Planetsvs.Stellaractivity
3
HabitabilityinGl581'splanets
FewJupiter-massplanets,manyNeptunes
Planet-metallicitycorrelation?
X.BonfilsGliese581
ThesearchforplanetsaroundMdwarfs
Dataanalysis
ThesearchwithHARPS
Sensus
ThesearchwithHARPS
InterestsofMdwarfs
HARPSsample
N =100
Δt=4years
N nights ≂40 rv <1ms -1
X.BonfilsGliese581
ThesearchforplanetsaroundMdwarfs
Dataanalysis
ThesearchwithHARPS
Sensus
Status
RVProgrammes
N Total ≂300Mdwarfs
HARPS+ELODIE+Keck+Lick+UVES+HET
6planetsaround4hosts
µ-lensingsurveys
representativetargets seetalksbyJ.-P.Beaulieu,D.Kubas&A.Cassan
4planets,4hosts
0.010.1110M
p (sini)[M Jup ]M p (sini)[M Jup ]10 0 10 1 10 2 10 3 10 4
P[days]P[days]
X.BonfilsGliese581
ThesearchforplanetsaroundMdwarfs
Dataanalysis
RVdata
Kepleriananalysis
Planetsvs.Stellaractivity
RVdata
Gl581
M3dwarf
0.3M 6.3pc m V =10.6
RadialVelocitydata
50RVmeasurements
t exp =900s RV ≂0.9ms -1 →≂1.5nightof3.6-mtelscope
σ=9.58ms-1
¯χ2
=120 -20-1001020RV-
[ms -1 ]RV-[ms -1 -1/2 ]PSD[arbHz -1/2 ]1101001000Period[day]Period[day] X.BonfilsGliese581
ThesearchforplanetsaroundMdwarfs
Dataanalysis
RVdata
Kepleriananalysis
Planetsvs.Stellaractivity
AhotNeptune...
1-planetKeplerianModel
ParameterGl581b
P[day]5.4
e0.(fixed) ω[deg]0.(fixed)
K[ms -1 ]13.2 m 2 sini[M ]16.6 a[AU]0.041 Bonfilsetal.2005,A&A44315
-20-1001020RV-γ[ms -1 ]RV-γ[ms -1 ]00.250.50.751φφ-25025O-C[ms -1 ]O-C[ms -1 X.BonfilsGliese581
ThesearchforplanetsaroundMdwarfs
Dataanalysis
RVdata
Kepleriananalysis
Planetsvs.Stellaractivity
...andtwosuperEarths 3-planetKeplerianModel
ParameterGl581bcd
P[day]5.412.984
e0.020.160.20 ω[deg]273267295
K[ms -1 ]12.53.02.5 m 2 sini[M ]15.75.07.7 a[AU]0.0410.0730.25 σ(O-C)=1.2ms
-1 Udryetal.2007
A&Ainpress.
X.BonfilsGliese581
ThesearchforplanetsaroundMdwarfs
Dataanalysis
RVdata
Kepleriananalysis
Planetsvs.Stellaractivity
ThecaseofGJ674
σ=0.82ms-1
χ2 =2.57 -10010RVplanet1[ms -1 ]RVplanet1[ms -1 ]-10010RVplanet2[ms -1 ]RVplanet2[ms -1 ]00.250.50.751φφ-505O-C[ms -1 ]O-C[ms -1 2-planetKeplerianModel
ParameterGJ674bGJ674c
P[day]4.735
e0.20.2 ω[deg]143113
K[ms -1 ]8.705.06 m 2 sini[M ]11.112.6 a[AU]0.0390.147 X.BonfilsGliese581
ThesearchforplanetsaroundMdwarfs
Dataanalysis
RVdata
Kepleriananalysis
Planetsvs.Stellaractivity
ThecaseofGJ674
Photometry
P var ≂35days ?2 nd signalislikely causedbyaspot ΔF=-0.013sin(2π/35.68+54259.93)
-1/2 ]PSD[arbHz -1/2 ]1101001000Period[day]Period[day] HαCaIIH+K
-505RV[m/s]RV[m/s]012345IndexIndex HαCaIIH+K
012345IndexIndex00.20.40.60.81φφ
Hα 01020PowerPower
CaIIH+K
SpectralIndices
P var ≂35days ?signal@35daysislikelyaspot X.BonfilsGliese581
ThesearchforplanetsaroundMdwarfs
Dataanalysis
RVdata
Kepleriananalysis
Planetsvs.Stellaractivity
ThecaseofGJ674
σ=0.82ms-1
χ2 =2.57 -10010RVplanet1[ms -1 ]RVplanet1[ms -1 ]-10010RVplanet2[ms -1 ]RVplanet2[ms -1 ]00.250.50.751φφ-505O-C[ms -1 ]O-C[ms -1 2-planetKeplerianModel
ParameterGJ674bSpot
P[day]4.735
e0.20.2 ω[deg]143113
K[ms -1 ]8.705.06 m 2 sini[M ]11.112.6 a[AU]0.0390.147 Bonfilsetal.2007A&Ainpress.
X.BonfilsGliese581
ThesearchforplanetsaroundMdwarfs
Dataanalysis
RVdata
Kepleriananalysis
Planetsvs.Stellaractivity
Thevery-lowactivitylevelofGl581
Lowrotation
vsini<1kms -1 ?lowP rot Spectroscopicindicators
averylowCaIIemission withnosignificantvariationatanyperiod ?lowP rot &lowspotcoverage Photometry
K s [ms -1 ]≂6.5f 0.9 s vsini (Saar&Donahue1998) P≂84dayscomputedobserved
GJ6741.7%2.6%
Gl5812.6%<1%
A]Wavelength[
A] Gl581 GJ674 X.BonfilsGliese581
ThesearchforplanetsaroundMdwarfs
Dataanalysis
HabitabilityinGl581'splanets
FewJupiter-massplanets,manyNeptunes
Planet-metallicitycorrelation?
HabitabilityinGl581'ssystem
Temperatureestimates
T p (A=0.6)T p (A=0.3) Gl581c270-320K
Gl581d150-170K
greenhouselikelyincreasesT p T p highlydependentof atmosphere needdirectobs. fromvonBlohetal.(2007) ?wehavestartedtoprobethem p andtheT p rangesofhabitableplanets X.BonfilsGliese581
ThesearchforplanetsaroundMdwarfs
Dataanalysis
HabitabilityinGl581'splanets
FewJupiter-massplanets,manyNeptunes
Planet-metallicitycorrelation?
FewJupiter-massplanets,manyNeptunes
FewJupiter-massplanets...
FGK:≂1%havehotJupiter,
Mdwarfs:NohotJupiter,
only1systemwithgiantplanets(P<1500days) P(d=1;N
=300;f p =4%)<10 -6 ?adeficitofJupiter-massplanets ...manyNeptunes 0hotJupiter
4hotNeptunes
for≂300targets ?hotNeptunesaremorefrequent thanhotJupiter(confidencelevel=97%) Bonfilsetal.2007
X.BonfilsGliese581
ThesearchforplanetsaroundMdwarfs
Dataanalysis
HabitabilityinGl581'splanets
FewJupiter-massplanets,manyNeptunes
Planet-metallicitycorrelation?
Planet-metallicitycorrelation?
[Fe/H]distributionofhosts w/planets:<[Fe/H]>=-0.08dex /wplanets:<[Fe/H]>=-0.18dex →Δ<[Fe/H]>=0.1dex KS-test=11%
notethathotsofgiantplanets occupythehigh-[Fe/H]tail Bonfilsetal.2005,2007
X.BonfilsGliese581
Conclusion
Conclusion
Mdwarfsaregreattargets
buttakecareofthestellaractivity withthem, X.BonfilsGliese581
quotesdbs_dbs7.pdfusesText_13
The Lick-Carnegie Exoplanet Survey: A 31 Earth-Mass Planet