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Transiting Extrasolar Planets di d b th XO P j tdiscovered by the XO Project
Museum and Planetarium BriefingMuseum and Planetarium Briefing
Peter R. McCulloughPeter R. McCulloughMay 1 2008May 1 2008May 1, 2008May 1, 2008
Copyright Notice
Many or most of the images in this presentation may have copyright restrictions Do not re-publish themrestrictions. Do not re-publish them without confirming the suitability of doing so.
XO data distilledThe special star’s …
• Position (RA DEC)• Position (RA, DEC)
• Time
• DepthDepth
• Width
• Period
Approximately 10 bytes of information!
XO data rateE h l i h XO hEach clear night, XO gathers…
• as much data as HST• 1 billion pixels• 1000 images• 1000 images• 100 epochs of 10000 stars suitablefor transit detection
XO observes each target for months.
XO data rateE h l i h XO hEach clear night, XO gathers…
•1 billion pixels• 2 Gbytes• the equivalent of 1 000 000• the equivalent of 1,000,000 printed ASCII pages
After operating for 4 years XOAfter operating for 4 years, XO has accumulated the equivalent of a forest of 4000 stacks of paper like the one under Bill Gates.
If printed, XO data would cost, at $0.01/page, $10,000 per night.
Summary of Transiting Extrasolar Planets 1 year ago May 2007: N = 17
“Traditional” RV surveys“Traditional” RV surveysMarcy et al (HD 209458)Marcy et al (HD 209458)
( ) ( )
1 year ago, May 2007: N = 17
HotHot--Neptunes (GJ436)Neptunes (GJ436)
Photometric surveys:Photometric surveys:yyHAT: HAT: 2.5 bright (V=82.5 bright (V=8--12)12)XO: XO: 3 bright (V=103 bright (V=10--11)11)TrES: TrES: 2.5 bright (V=11.4, V=11.8) 2.5 bright (V=11.4, V=11.8) g ( , )g ( , )WASP:WASP: 2 bright (V=11.8, V=12.0)2 bright (V=11.8, V=12.0)OGLE: OGLE: 5 faint (V ~15) (10b, 56b, 111b, 113b, 132b)5 faint (V ~15) (10b, 56b, 111b, 113b, 132b)Others Others 2 faint (Lupus, SWEEPS)2 faint (Lupus, SWEEPS)Others Others 2 faint (Lupus, SWEEPS)2 faint (Lupus, SWEEPS)OthersOthers (in process)(in process)
MetalicityMetalicity--filtered RV surveysfiltered RV surveysN2K (HD 149026, V=8)N2K (HD 149026, V=8)OHP (HD 189733, V=8)OHP (HD 189733, V=8)
“Traditional” RV surveys“Traditional” RV surveysSummary of Transiting Extrasolar Planets
May 1 2008: N=46 Traditional RV surveysTraditional RV surveysMarcy et al (HD 209458)Marcy et al (HD 209458)HotHot--Neptunes (GJ436)Neptunes (GJ436)TransitSearch org (HD 17156)TransitSearch org (HD 17156)
May 1, 2008: N=46
TransitSearch.org (HD 17156)TransitSearch.org (HD 17156)
Photometric surveys:Photometric surveys:HAT: HAT: 7 bright (V=87 bright (V=8--12)12)XO: XO: 3 bright (V=103 bright (V=10--12), (more, May 20)12), (more, May 20)TrES: TrES: 4 bright (V=114 bright (V=11--12) 12) WASP:WASP: 5[+10] bright (V<13)5[+10] bright (V<13)OGLE: OGLE: 7 faint (V ~15)7 faint (V ~15)Corot:Corot: 2 faint (V=12.6, V=13.6)2 faint (V=12.6, V=13.6)Others: Others: 3 very faint (Lupus, SWEEPS)3 very faint (Lupus, SWEEPS)Others Others (in process)(in process)
MetalicityMetalicity filtered RV surveysfiltered RV surveysMetalicityMetalicity--filtered RV surveysfiltered RV surveysN2K (HD 149026, V=8)N2K (HD 149026, V=8)OHP (HD 189733, V=8)OHP (HD 189733, V=8)
XO targets Bright Stars that allow …Absorption Spectra of Planetary AtmosphereAbsorption Spectra of Planetary AtmospherePrecise photometry and timing of transitsPrecise photometry and timing of transits
Oblateness (rotation rate) of planetOblateness (rotation rate) of planetOblateness (rotation rate) of planetOblateness (rotation rate) of planetRings, Satellites of planetRings, Satellites of planetPerturbations from TP: Perturbations from TP: δ(δ(TOA) ~ many secondsTOA) ~ many secondsLimb darkening and star spotsLimb darkening and star spotsLimb darkening and star spotsLimb darkening and star spots
Secondary EclipseSecondary EclipseTemperature, Temperature, δδf/f ~ ( Tf/f ~ ( Tpp/T/Tss ) ( R) ( Rpp/R/Rss ))22 ~ 0.4% in IR~ 0.4% in IRM f R b i h f l ’ “ f ”M f R b i h f l ’ “ f ”
Extrasolar Visions Inc.
Map of IR brightness of planet’s “surface”Map of IR brightness of planet’s “surface”Eccentricity better than RV methodEccentricity better than RV methodAlbedo, Albedo, δδf/f ~ 0.02% x optical albedof/f ~ 0.02% x optical albedo
Key: Key: donedone and feasible but not demonstrated yetand feasible but not demonstrated yet
XO Cameras d and
Robotic mount
Unique aspects: 1) Two cameras (pilot & copilot)2) 0.4-0.7 micron bandpass3) Powered drift scanning (like SDSS)
XO Extended Team
RBBG
TVCF PH
MFEG FM
GM
Paul HowellPaul HowellXO
Ron BissingerRon BissingerMik FlMik Fl Franco MalliaFranco Mallia
Gianluca MasiGianluca MasiT V tT V t
Mike FleenorMike FleenorCindy FooteCindy FooteEnrique GarciaEnrique Garcia Tonny VanmunsterTonny VanmunsterEnrique GarciaEnrique GarciaBruce GaryBruce Gary
XO’s Extended Team:
E T = Advanced Amateur AstronomersE T = Advanced Amateur AstronomersE.T. = Advanced Amateur AstronomersE.T. = Advanced Amateur Astronomers(Olympic athletes are amateurs too…)(Olympic athletes are amateurs too…)
Global longitude coverageGlobal longitude coverageMore and Better photometry (next slide)More and Better photometry (next slide)“A spectrum saved is a spectrum earned.”“A spectrum saved is a spectrum earned.”
LocationLocationXO Planet 1 a.k.a. XO-1b
LocationLocation16h +28deg16h +28degCorona BorealisCorona Borealis
StarStarV = 11.2 magV = 11.2 magggSp. Type = G1 VSp. Type = G1 VD = 200 pcD = 200 pc
PlanetPlanetPeriod = 3.94 daysPeriod = 3.94 daysMass = 0.9 M_JupiterMass = 0.9 M_JupiterRadius = 1.3 R_JupiterRadius = 1.3 R_Jupiter
Additi l l t i t ? N t tAdditi l l t i t ? N t tAdditional planets in system? Not yet…Additional planets in system? Not yet…
AAS Abstract (May 2007)
Title: XO-2b: A Transiting Hot Jupiter in a Metal-rich Common Proper Motion Binary e: O b: a s g o Jup e a e a c Co o ope o o a yAuthors: Burke, Christopher J. (STScI), McCullough, P. R. (STScI), Valenti, Jeff A.
(STScI), Summers, F. J. (STScI), Stys, J. E. (STScI), Johns-Krull, C. M (Rice Univ.), Janes, K. A. (Boston Univ.), Heasley, J. N. (Univ. Hawaii), Bissinger, R. ), , ( ), y, ( ), g ,(Racoon Run Obs.), Fleenor, M. (Volunteer Obs.), Foote, C. N. (Vermillion Cliffs Obs.), Garcia-Melendo, E. (Duran Obs.), Gary, Bruce L. (Hereford AZ Obs.), Howell, P. J. (Boston Univ.), Mallia, F. (Campo Catino Obs.), Masi, G. (Bellatrix Obs.), Vanmunster, T. (CBA Obs.)
Abstract: XO-2b, the second transiting extrasolar planet from the XO Project (McCullough et al. 2005), is approximately Jupiter-size and 0.6 Jupiter-mass with an orbital period of 2.6 days. The stellar host, XO-2, is a V=11, early K dwarf which is metal rich, [Fe/H]=+0.44. XO-2 has a high proper motion and has a common proper motion stellar companion. The two stars are nearly identical twins, with very similar
d i d Th l b l k f d f i lspectra and apparent magnitudes. The global network of amateur and professional astronomers organized by the XO project confirmed the XO-2b transit light curve two days after being notified that it was a high-priority candidate, and radial velocities confirmed its planetary mass eight days after thatvelocities confirmed its planetary mass eight days after that.
AAS Abstract (May 2007)Title: The Unusual Transiting Extra-Solar Planet Orbiting XO-3
Christopher M. Johns-Krull1, P. M. McCullough2, C. J. Burke2, J. A. Valenti2, K. A. Janes3, J. N. Heasley4, R. Bissinger5, M. Fleenor6, C. N. Foote7, E. Garcia-Melendo8, B. L. Gary9, P. J. Howell3, F. Mallia10, G. Masi11, L. A. Prato12, T. Vanmunster13Vanmunster131Rice Univ., 2STScI, 3Boston Univ., 4Univ. Hawaii, 5Racoon Run Obs., 6Volunteer Obs., 7Vermillion Cliffs Obs., 8Duran Obs., 9Hereford AZ Obs., 10Campo CatinoObs., 11Bellatrix Obs., 12Lowell Obs., 13CBA Obs..
Abstract: We report the discovery of a massive planet (≈12 MJUP) in an eccentric orbit (e ≈ 0.2) around the F6 star XO-3. This planet transits the 10th magnitude star every 3 19 days This system is unusual for a number of reasons XO 3b is one of the most3.19 days. This system is unusual for a number of reasons. XO-3b is one of the most massive planets discovered around any star for which the orbital period is less than 10 days. The mass is near the deuterium burning limit of 13 MJUP which is a proposed boundary between planets and brown dwarfs. Burrows et al. (2001) propose that formation in a disk or formation in the interstellar medium in a manner similar to stars is a more logical way to differentiate planets and brown dwarfs. Our current observations are not adequate to address this distinction. XO-3b is also unusual in that its eccentricity is large given its relatively short orbital periodunusual in that its eccentricity is large given its relatively short orbital period. Finally, the star XO-3 is somewhat metal poor, with [Fe/H] ≈ -0.25. We will present our observations leading to this discovery and discuss the implications of this system for models of planet formation.
Radius versus Mass --- expanded scales
M d fRare hereTransiting hot Jupiters Planet-sized
M dwarfsRare here
Jupiters n zbrown-dwarf edge
ont 2
005
Fred
eric
Po
XO Constellation, Phase 1 = 3 units
+
Operational 2003 2007 Operational 2008Operational 2003-2007Haleakala
Operational 2008-Haleakala
1 unit ($50k) = 2 lenses, 2 CCDs, 1 mount, 3 computers
Further Reading
Websites:Websites:XO P j t htt //XO P j t htt // i t t i d / / /i t t i d / / /XO Project: http://wwwXO Project: http://www--int.stsci.edu/~pmcc/xo/int.stsci.edu/~pmcc/xo/Pont’s site: http://www.inscience.ch/transits/Pont’s site: http://www.inscience.ch/transits/Exoplanet Encyclopedia: http://exoplanet.eu/Exoplanet Encyclopedia: http://exoplanet.eu/ P bl P blXO PublicationsXO PublicationsXOXO--3 3 arXiv:0712.4283arXiv:0712.4283XOXO--2 2 arXiv:0705.0003arXiv:0705.0003XOXO--1 1 arXiv:astroarXiv:astro--ph/0605414ph/0605414Search Technique: Search Technique:
arXiv:astroarXiv:astro--ph/0505560ph/0505560arXiv:astroarXiv:astro--ph/0703331ph/0703331
Articles about XO:Articles about XO:Sky & Telescope Sep 2006 issueSky & Telescope Sep 2006 issuey p py p p(Knutson popular article on E.T.)(Knutson popular article on E.T.)