Search for HAT-P-13 c transit

VALIDITY: 12. 3. 2010 - 30. 6. 2010
AUTHOR: Benjamin Nelson, 12. 3. 2010
 
------- NEW 25th March 2010 ---------
Refined prediction of HAT-P-13 possible transit.
Joshua N. Winn et al. has published paper The HAT-P-13 Exoplanetary System: Evidence for Spin-Orbit Alignment and a Third Companion with new precise radial velocity data. The refined orbit of HAT-P-13 c lead to predicted possible
transit window centered at JD 2455315.2 +/- 1.9 (28th April, 2010, 17h UT).
------- NEW 25th March 2010 ---------

During April 2010, the observing window for transits of outer planet of HAT-P-13 double planetary system (HAT-P-13 c) will appear. Observers are called to join the observing campaign and try to find transits of this 428.5 day orbit exoplanet. More often HAT-P-13 b transit observations are also very encouraged (see bellow).

Benjamin Nelson and colleques from University of Florida are enouncing observing campaign on this system, which should afford more information about HAT-P-13 b and c exoplanets.

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HAT-P-13, to summarize, is a 10.6 magnitude, 1.22 solar mass star with a 2.9 day, transiting planet (b) and a ~430 day outer planet (c) with a highly eccentric orbit (~0.7).

A lot of dynamical work can and has been done on this system. The transit probability, given the inclination distribution from these two papers (Mardling, 2010 and Beatty & Seager, 2010) is about 8% and the maximum transit duration is about 15 hours.

Given the uncertainty in the orbital period, the planet may transit on a completely different date than predicted in the discovery paper, Bakos et al. 2009 - April 12th, 2010 at 9 AM UTC.

Matt Payne (University of Florida) has done a histograms of the most likely times using MCMC algorithm. It predicts, that probably transit of HAT-P-13 c should occur between 9th and 24th April 2010 (2455302.5 +8.2 / -6.5 days). Where uncertainties are 1-sigma, i.e. they indicate the spread that would be required to encompass 68% of the MCMC data. See pictures:




Not only search for a "c" planet. But "b" planet transit observations are strongly ecouraged.

High precision observations of the inner planet can potentially yield a lot of information regarding the relative inclination in the system. Such observations should preferentially take place over an approximately 50-60 day period straddling the date of pericenter passage of the outer planet, i.e. approximately:
JD 2455296 - 2455360, i.e. April 9th - June 12th



DATA POSTING
HAT-P-13 b transit observations should be submitted to TRESCA & ETD database using the model-fitting application form.
HAT-P-13 c data should be sent to Benjamin Nelson, coordinator of the campaign.

> Transit predictions for inner planet "b" (ETD)

> Inside Information (oklo.org) NEW 22nd March 2010

> Two-Planet Perturbations for 2010 (by Bruce Gary) NEW 22nd March 2010

> HAT-P-13: good news and bad news at oklo.org (NEW 7th April 2010)

REFERENCES:
- Bakos et al. 2009: http://arxiv.org/abs/0907.3525
- Mardling, 2010: http://arxiv.org/abs/1001.4079
- Beatty & Seager, 2010: http://arxiv.org/abs/1002.3168


Campaign text compiled by Lubos Brat