J/ApJ/794/110 HARPS timeseries data for HD41248 (Jenkins+, 2014)
The curious case of HD 41248. A pair of static signals buried behind red noise.
Jenkins J.S., Tuomi M.
<Astrophys. J., 794, 110 (2014)>
=2014ApJ...794..110J 2014ApJ...794..110J (SIMBAD/NED BibCode)
ADC_Keywords: Stars, G-type ; Radial velocities
Keywords: planetary systems - stars: fundamental parameters -
stars: individual: HD41248 - stars: rotation
Abstract:
Gaining a better understanding of the effects of stellar-induced
radial velocity noise is critical for the future of exoplanet studies
since the discovery of the lowest-mass planets using this method will
require us to go below the intrinsic stellar noise limit. An
interesting test case in this respect is that of the southern solar
analog HD 41248. The radial velocity time series of this star has been
proposed to contain either a pair of signals with periods of around 18
and 25 days, which could be due to a pair of resonant super-Earths, or
a single and varying 25 day signal that could arise due to a complex
interplay between differential rotation and modulated activity. In
this work, we build up more evidence for the former scenario, showing
that the signals are still clearly significant, even after more than
10 yr of observations, and they likely do not change in period,
amplitude, or phase as a function of time, the hallmarks of static
Doppler signals. We show that over the last two observing seasons,
this star was more intrinsically active and the noise reddened,
highlighting why better noise models are needed to find the lowest
amplitude signals, in particular, models that consider noise
correlations. This analysis shows that there is still sufficient
evidence for the existence of two super-Earths on the edge of, or
locked into, a 7:5 mean motion resonance orbiting HD 41248.
Description:
We modeled the HARPS radial velocities of HD 42148 by adopting the
analysis techniques and the statistical model applied in Tuomi et al.
(2014, 1405.2016). This model contains Keplerian signals, a
linear trend, a moving average component with exponential smoothing,
and linear correlations with activity indices, namely, BIS, FWHM, and
chromospheric activity S index. We applied our statistical model
outlined above to the full data set of radial velocities for HD 41248,
combining the previously published data in Jenkins et al.
(2013ApJ...771...41J 2013ApJ...771...41J) with the newly published data in Santos et al.
(2014, J/A+A/566/A35), giving rise to a total time series of 223 HARPS
(Mayor et al. 2003Msngr.114...20M 2003Msngr.114...20M) velocities.
Objects:
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RA (ICRS) DE Designation(s)
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06 00 32.78 -56 09 42.6 HD 41248 = HIP 28460
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 48 223 HARPS timeseries data for HD41248
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See also:
J/A+A/566/A35 : Radial velocities of HD 41248 (Santos+, 2014)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 15 F15.7 d BJD Barycentric Julian Date of observation
17- 23 F7.2 m/s RVel Radial velocity
25- 28 F4.2 m/s e_RVel Uncertainty in RVel
30- 34 F5.3 [-] S-index Chromospheric activity S-index
36- 40 F5.2 m/s BIS Bisector inverse slope
42- 48 F7.2 m/s FWHM Full-Width at Half-Maximum
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 15-May-2017