CoRoT-7
AXA Light Curves
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    Comments
    Basic data
    Table of AXA (amateur) transit measurements
    Transit LCs - amateur
    Transit LCs - professional
    OOT LCs
    Finder images

Comments

This BTE has a depth too small for amateur observers, ~ 1/3 mmag! 

Basic data

    RA = 06:43:49.5, DE = -01:03:47
    Season = January 1
    B = 12.52, V = 11.67, R = 11.3, I = 10.8, J = 10.301, K = 9.806
    HJDo = 4398.0767 ± 0.0015 & P = 0.853585 ± 0.000024 days (as listed at Extrasolar Planets Encyclopaedia)
    Depth =  0.335 ± 0.0012 mmag
    Length =  1.25 ± 0.05 hr
    Fp = 0.21 ± 0.04, F2 =  ±

Amateur observations

   


Various photometry apertures with 8 reference stars show depths of 47 ± 6 mmag, 37 ± 5 mmag and 37 ± 6 mmag. Lengths are 1.06 ± 0.11 hr, 1.06 ± 0.11 hr & 2.13 ± 0.24 hr. JDmid = 5538.4340, 5538.4337 & 5538.4425 ± 0.0029.

This is a puzzling observation. Yes, the ephemeris for CoRoT-7b calls for a transit at this time, but CoRoT-7b is a super-Earth producing a transit depth of only ~ 1/3 mmag! How come the depth for this event was ~ 100 times larger!

The ephemeris at Extrasolar Planets Encyclopaedia is (2454398.0767 ± 0.015) + E * (0.853585 ± 0.000024), so for E = 1336 we predict BJD = 2455538.4663 ± 0.0353, and since JD-HJD at this date is -0.0046 day (-6.6 min) the ephemeris mid-transit JD is 5538.4616 ± 0.0353. Toni reports mid-transit JD values that correspond to -40, -40 & -28 ± 51 minutes (i.e., earlier), . The measured mid-transit time is therefore compatible with the expected transit time for CoRoT-7b!

Toni is sharing his images with others and their analysis will be presented below when available.
 



Light Curves - Professional

 
LC taken from Leger et al, 2009.



Out-of-Transit (OOT) Light Curves


 

Finder Charts



References

Discovery paper: Leger et al, 2009, http://exoplanet.eu/papers/corot-7b_phot_v37.pdf  


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WebMaster: Bruce L. Gary.  Nothing on this web page is copyrighted. This site opened:  2009.08.01.  Last Update:  2010.12.09