HAT-P-9b
 Size comparison of HAT-P-9b with Jupiter. | |
| Discovery | |
|---|---|
| Discovered by | Shporer et al. |
| Discovery site | Cambridge, Massachusetts |
| Discovery date | June 26, 2008 |
| Transit(SuperWASP) | |
| Orbital characteristics | |
| 0.0528 ± 0.002 AU (7,900,000 ± 300,000 km) | |
| Eccentricity | ~0.0012 |
| 3.92289 ± 0.00004d | |
| Star | HAT-P-9 |
| Physical characteristics | |
| 1.4 ± 0.06RJ | |
| Mass | 0.78 ± 0.09MJ |
Meandensity | 0.38g/cm3 |
| 10.3m/s2(34ft/s2) 1.05g | |
HAT-P-9b,formally namedAlef,[1]is anexoplanetapproximately 1500light yearsaway in theconstellationAuriga.This planet was found by thetransit methodon June 26, 2008. It has amass78% that ofJupiterand aradius140% that of Jupiter. As with most transiting planets, this planet is ahot Jupiter,meaning this Jupiter-like planet orbits extremely close to its parent star, taking only 3.92 days to orbit.[2]
The study in 2012, utilizing aRossiter–McLaughlin effect,have determined the planetary orbit is mildly misaligned with the rotational axis of the star, misalignment equal to -16±8°.[3]
The name Alef was selected in theNameExoWorldscampaign byIsrael,during the 100th anniversary of theIAU.Alef is the first letter in theHebrewalphabet and also meansbull.[1]
References
[edit]- ^ab"Approved names".NameExoworlds.Retrieved2020-01-02.
- ^Shporer, Avi; et al. (2009). "HAT-P-9b: A Low-Density Planet Transiting a Moderately Faint F Star".The Astrophysical Journal.690(2): 1393–1400.arXiv:0806.4008.Bibcode:2009ApJ...690.1393S.doi:10.1088/0004-637X/690/2/1393.S2CID930937.
- ^Albrecht, Simon; Winn, Joshua N.; Johnson, John A.; Howard, Andrew W.; Marcy, Geoffrey W.; Butler, R. Paul; Arriagada, Pamela; Crane, Jeffrey D.; Shectman, Stephen A.; Thompson, Ian B.; Hirano, Teruyuki; Bakos, Gaspar; Hartman, Joel D. (2012), "Obliquities of Hot Jupiter host stars: Evidence for tidal interactions and primordial misalignments",The Astrophysical Journal,757(1): 18,arXiv:1206.6105,Bibcode:2012ApJ...757...18A,doi:10.1088/0004-637X/757/1/18,S2CID17174530
External links
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