Measuring the Spin-Orbit Alignments of Transiting Exoplanetary Systems:

1
Measuring the Spin-Orbit Alignments of Transiting
Exoplanetary Systems The Case for TrES-1 Norio
Narita, Keigo Enya, Bun'ei Sato, Yasuhiro Ohta,
Joshua N. Winn, Yasushi Suto, Atsushi Taruya,
Edwin L. Turner, Wako Aoki, Motohide Tamura, Toru
Yamada, Yuzuru Yoshii
One can test the planet migration models by
measuring the spin-orbit alignments in
exoplanetary systems!
The Case for TrES-1

• Parameters of TrES-1
• V 11.8 (relatively faint)
• K0V star (small rotational velocity)
• duration 150 min
• i (orbital inclination) 90 deg
• challenging target for the RM observation

• Observations
• simultaneous spectroscopic/photometric
  observations
• Subaru 8.2 m telescope at Mauna Kea (Hawaii)
• MAGNUM 2 m telescope at Haleakala (Maui)
• observing date UT 2006 June 21
• RV precision 10 15 m/s
• photometric precision 2mmag

constraints on ? 30 21 deg (a)
See details in Narita et al. (2007) (astro-ph/0702
707)
best-fitting model (with/without constraint on
VsinIs)
Future Prospects of Our Project

• We have demonstrated that the RM effect is
  detectable for
• a relatively faint (V12) target
• Our TrES-1 result is the first demonstration for
  a V12 host star
• New targets in this category have been
  discovered
• We can measure spin-orbit alignments of those
  targets
• We plan to conduct further RM observations for
  newly discovered
• targets with Subaru/MAGNUM telescopes in
  2007
• We will present the distribution of spin-orbit
  alignments of
• transiting exoplanetary systems
• Such observational information will allow us to
  test planet
• migration models in the near future