J/A+A/539/A28 New transit photometry for super-Earth 55 Cnc e (Gillon+, 2012)
Improved precision on the radius of the nearby super-Earth 55 Cnc e.
Gillon M., Demory B.-O., Benneke B., Valencia D., Deming D., Seager S.,
Lovis C., Mayor M., Pepe F., Queloz D., Segransan D., Udry S.
<Astron. Astrophys. 539, A28 (2012)>
=2012A&A...539A..28G 2012A&A...539A..28G
ADC_Keywords: Stars, double and multiple ; Planets ; Photometry, infrared
Keywords: techniques: photometric - binaries: eclipsing - planetary systems -
stars: individual: 55 Cnc
Abstract:
We report on new transit photometry for the super-Earth 55 Cnc e
obtained with Warm Spitzer/IRAC at 4.5um. An individual analysis of
these new data leads to a planet radius of
2.21+0.15-0.16R{earth}, in good agreement with the values
previously derived from the MOST and Spitzer transit discovery data. A
global analysis of both Spitzer transit time-series improves the
precision on the radius of the planet at 4.5um to
2.20±0.12R{earth}. We also performed an independent analysis of
the MOST data, paying particular attention to the influence of the
systematic effects of instrumental origin on the derived parameters
and errors by including them in a global model instead of performing a
preliminary detrending-filtering processing. We deduce from this
reanalysis of MOST data an optical planet radius of
2.04±0.15R{earth} that is consistent with our Spitzer infrared
radius
Description:
We monitored 55Cnc with Spitzer on 20 June 2011 from 09h08 to
15h02 UT, corresponding to a transit window of 55Cnc e as computed
from our transit ephemeris presented in Demory et al., 2011, Cat.
J/A+A/533/A114.
Objects:
-----------------------------------------
RA (2000) DE Designation(s)
-----------------------------------------
08 52 35.8 +28 19 51 55 Cnc = HR 3522
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
irac1.dat 92 5059 IRAC 4.5 microns time-series photometry, 06/01/2011
irac2.dat 92 6197 IRAC 4.5 microns time-series photometry, 20/06/2011
most1.dat 73 641 *MOST time-series photometry, 07-09/02/2011
most2.dat 73 643 *MOST time-series photometry, 09-11/02/2011
most3.dat 73 652 *MOST time-series photometry, 12-15/02/2011
most4.dat 72 653 *MOST time-series photometry, 15-17/02/2011
most5.dat 73 653 *MOST time-series photometry, 17-19/02/2011
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Note on most1.dat, most2.dat, most3.dat, most4.dat, most5.dat: MOST stands
for "Microvariability and Oscillations of STars", and is a Canadian
microsatellite equipped with a 15 cm telescope and CCD photometer,
covering the visible spectrum 350-700nm
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See also:
J/A+A/533/A114 : Transit of super-Earth 55 Cnc e (Demory+, 2011)
Byte-by-byte Description of file: irac1.dat irac2.dat
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Bytes Format Units Label Explanations
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1- 19 F19.11 d BJD UTC Baselian Julian date
21- 37 F17.15 --- Flux Normalized flux
39- 58 E20.16 --- e_Flux rms uncertainty on Flux
60- 75 F16.13 pix Xpos X position
77- 92 F16.13 pix Ypos Y position
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Byte-by-byte Description of file: most?.dat
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Bytes Format Units Label Explanations
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1- 14 F14.6 d BJD UTC Baselian Julian date
16- 23 F8.6 --- Flux Normalized flux
25- 32 F8.6 --- e_Flux rms uncertainty on Flux
34- 42 F9.6 pix dx Offset in X
44- 52 F9.6 pix dy Offset in Y
54- 63 F10.7 --- Bck Background counts (1)
64- 73 F10.7 --- B Magnetic field (1)
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Note (1): The magnetic field is in fact a calculated (not measured) value.
The background and magnetic field are not in physical units.
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Acknowledgements:
Michael Gillon, michael.gillon(at)ulg.ac.be
(End) Patricia Vannier [CDS] 05-Jan-2012