Super-Earth (radius = 2.7 x R_Earth, mass = 6.5 x M_Earth),
discovered by MEarth observing system at Mount Hopkins. I include it in the
BTE in spite of its faint V-mag partly bercause it's such an important exoplanet
and also because with a long wavelength filter (NIR is best choice, but
R-band or z-band will do) it's not so faint because the star is so red.
RA = 17:15:18.9, DE = +04:57:50
Season = June 13
V = 14.67, J=9.750, K=8.782 (B-V > 1.5, very red)
HJDo = 4999.712703 (126) and P = 1.5803925 (117) days (as listed in Schneider's Extrasolar Planets Encyclopaedia, HJDo corrected from earlier value)
Depth = 17.5 ± 1.5 mmag (NIR-band)
Length = 0.85 ± 0.10 hr (NIR-band)
Fp = 0.?? ± 0.??, F2 = 0.?? ± 0.??
b = 0.354
Table & Plots of Amateur Observations -
Amateur Light Curves
Gregor Srdoc (Croatia) observed GJ 1214 on 20 nights and produced this phase-folded LC. The data include 3 transit events but are mostly OOT.
This phase-folded LC can be used to rule out the presence of a second transiting exoplanet at the 10 mmag level (Gregor writes), keeping in mind that a second planet transit won't have the same period and therefore won't appear "in phase" with the primary exoplanet "b". Gregor used a 12-inch telescope and SBIG ST-7XME CCD. Each night the star filed was placed a the same pixel location and an autoguider kept the star field fixed to the pixel field throughout the observing session. His filter was a longpass R (Baader Planetarium). Defocusing allowed for exposure times of 240 seconds. The photometric readings of target and reference stars were de-trended and phase folded using Peranso (by Vanmunster).
Professional Light Curves
See caption for this figure in Amateur Light Curves section, above.
Beware the (apparent) Delta Scuti variable (GSC 408:113) located 1.3 'arc south of GJ 1214 when choosing reference stars. Colin Littlefield has measured the "variable" on several occasions to have a period of ~ 6 hrs with an amplitude of ~ 0.1 magnitude. (Image from SkyMap)
Discovery paper: Charbonneau et al, 2009, http://fr.arxiv.org/abs/0912.3229
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L. Gary. Nothing on this web page is copyrighted. This site opened:
2009.12.20 . Last Update: 2010.07.16