AXA Light Curves

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    Basic data
    Table summary of transit measurements
    Transit LCs
    OOT LC
    Finder image

Comments - Updated 2009.09.05

This is a difficult exoplanet to observe because it's a double star with separation = 11"arc. You need really good seeing for use of a photometry aperture that restricts flux measurements to just the exoplanet star (~0.5 mag fainter). It's OK to include both stars in your photometry aperture, but please note that this was done in a header comment line. 

Basic Data - Updated 2009.09.22

    RA = 22:57:46.8, Decl = +38:40:30
    Season = September 09
    V ~ 10.2,
B-V = 0.7; B~10.9, V~10.2, R~9.81, I ~ 9.56  (for combined flux of stars A and B: B~9.8, V~9.1, R~8.77, I = 8.52)
    HJDo = 4363.94656 (72), Johnson et al, 2008 & P = 4.4652934 (93) day, Johnson et al, 2008 (as listed in Schneider's  Extrasolar Planets Encyclopedia)
HJDo = 4363.9463 (7) & P = 4.4653194 (13) from fit to data in AXA
    Depth = 13.0 ± 1.5 mmag if only the exoplanet star is measured, and 6.0 ± 1.5 if both stars are measured. Winn et al, 2007 report 14.0 ± 0.5 mmag (z-band).
    Length = 2.67 ± 0.2 (C & R-band), 2.65 ± 0.02 hr (z-band), Winn et al, 2007
    Fp = 0.44
± 0.05, F2 = 0.81 ± 0.15
    b = 0.70

Table Summary of Transit Light Curves - Updated 2009.09.22



The small depths near JD = 5060 probably is due to the photometry aperture including both components A and B (see finder image below).
The Depth median fit line is for the "single star" photometry data.


Transit Light Curves






9816SG2  The small depth probably is due to the photometry aperture including both components A nd B (see finder image below).     

Came early, whereas a week earlier it came late..

Transit was late. Depth is lower than for R-band, probably because CLR filter is bluer than R (& limb darkening will produce lower depth at bluer bands if exoplanet transit chord is close to star center). Length agrees. Good job for a 12-inch and using 10-second exposure times (with associated low duty cycle).

Out-of-Transit (OOT)

9819SG21  Defocused mode.

Finder Image

HAT-P-1b is Star "B" & orbits brighter star "A" located 11.3 "arc away.


Johnson, JOhn Asher et al, "Measurement of the Spin-Orbit Angle of Exoplanet HAT-P-1b", arXiv:0806.1734vJ, http://adsabs.harvard.edu/abs/2008arXiv0806.1734J

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WebMaster: Bruce L. GaryNothing on this web page is copyrighted. This site opened:  September 08, 2007 Last Update:  2009.09.26