J/ApJ/689/L149 Parameter variations of Gliese 436b transits (Coughlin+, 2008)
New observations and a possible detection of parameter variations in the
transits of Gliese 436b.
Coughlin J.L., Stringfellow G.S., Becker A.C., Lopez-Morales M.,
Mezzalira F., Krajci T.
<Astrophys. J., 689, L149-L152 (2008)>
=2008ApJ...689L.149C 2008ApJ...689L.149C
ADC_Keywords: Planets ; Stars, diameters ; Stars, variable
Keywords: planetary systems - stars: individual (Gliese 436)
Abstract:
We present ground-based observations of the transiting Neptune-mass
planet Gl 436b obtained with the 3.5m telescope at Apache Point
Observatory and other supporting telescopes. Included in this is an
observed transit in early 2005, over 2 years before the earliest
reported transit detection. We have compiled all available transit
data to date and perform a uniform modeling using the JKTEBOP code. We
do not detect any transit timing variations of amplitude greater than
∼1 minute over the ∼3.3 year baseline. We do however find possible
evidence for a self-consistent trend of increasing orbital
inclination, transit width, and transit depth, which supports the
supposition that Gl 436b is being perturbed by another planet of
≲12M{earth} in a nonresonant orbit.
Description:
We observed Gl 436 (J114211+264224) in the V filter on the nights
of 2008 April 7, April 28, and May 6 UT with the 3.5m telescope at
Apache Point Observatory (APO).
Objects:
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RA (2000) DE Designation(s)
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11 42 11.1 +26 42 24 Gliese 436b = GJ 436 b
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 125 58 Parameters derived from using the JKTEBOP code
with 1σ errors
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See also:
J/A+A/471/L51 : Spitzer observations of the hot Neptune GJ 436b (Gillon+,
2007)
J/A+A/475/1125 : Characterization of the hot Neptune GJ 436b (Demory+, 2007)
J/A+A/507/481 : GJ 436b and XO-1b transits (Caceres+, 2009)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1 A1 --- Mod Model type (1)
3- 6 I4 --- E ? Epoch of observation (2)
8- 25 A18 --- Source Source of Data (telescope or author)
27- 45 A19 --- BibCode Bibcode of author if relevent
47 A1 --- f_Source [ab] Precision on source (3)
49- 52 A4 --- Filt Filter (8um, B, H, I, R, V, None);
Johnson-Cousins system
54- 63 F10.5 d t0 ? HJD-2450000 (Heliocentric Julian Date)
of minimum
65- 71 F7.5 d e_t0 ? 1σ uncertainty in Tmin
73- 77 F5.2 deg i Orbital inclination
79- 82 F4.2 deg e_i 1σ uncertainty in i
84- 88 F5.3 Rsun R* Stellar radius (in solar radius)
90- 94 F5.3 Rsun e_R* 1σ uncertainty in R*
96- 99 F4.2 --- Rp Planetary radius in Earth radii (6371km)
101-104 F4.2 --- e_Rp 1σ uncertainty in Rp
106-110 F5.2 mmag Depth Depth of eclipse
112-115 F4.2 mmag e_Depth 1σ uncertainty in Depth
117-120 F4.1 min Width Width of eclipse
122-125 F4.1 min e_Width 1σ uncertainty in Width
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Note (1): Model type as follows:
V = Ratio of radii k=Rp/Rs allowed to vary.
F = Star and Planet radii fixed by fixing k.
Note (2): Epoch with E=0 the initial transit discovery of Gillon et al.
(2007A&A...472L..13G 2007A&A...472L..13G).
Note (3): Data source as follows:
a = Amateur Observer with data obtained from Bruce Gary.
http://brucegary.net/AXA/GJ436/gj436.htm.
b = Data were digitized from published plot.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 20-Jan-2011