Discovery of the secondary eclipse of HATP11 b (Corrigendum)
Hamburger Sternwarte, Universität Hamburg, Gojenbergsweg 112, 21029 Hamburg, Germany
Key words: planetary systems / stars: individual: HATP11 / techniques: photometric / methods: data analysis / errata, addenda
1. Reported ephemeris
Our reported midtransit time T_{0} contains a shift when compared to other data sets. After checking our analysis we found an error in the correction of the Kepler BJD times. In the original article we wrote that our determined T_{0} is given in BJD_{UTC}. However, this is only true for Kepler data up to release 19. For data releases after this (data release 20/21 onwards), the reported times in the Kepler data are correctly given in BJD_{TDB}^{1}. We checked the Kepler data we used and confirm that all the Kepler data has times in BJD_{TDB}. Thus, our reported T_{0} is in BJD_{TDB} as well.
We have changed Table 1 and Fig. 1 of the original paper and include the new versions in this corrigendum. The only difference is that we have not applied the subtraction of Δt = 66.184 s to T_{ref} of SanchisOjeda & Winn to convert it into BJD_{UTC}, and we now correctly state that our value of T_{0} is given in BJD_{TDB}; we note that the actual numerical value of T_{0} does not change. The other results in our original paper are not affected by this correction.
Fig. 1
Measurements of midtransit times from 206Kepler transits. The (magenta) line represents a firstorder polynomial fit to the errorweighted measurements. The lower panel shows the residuals with outliers removed. See caption and text of original paper for more detailed explanations. 

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2. Difference to T_{ref}
In Sect. 3.1 of the original paper we speculate on the origin of the time difference of about two minutes between T_{0} and T_{ref}; however, we were not able to provide a convincing answer to this inconsistency. After correction for our mistake concerning the time system, this difference ΔT between T_{0} and T_{ref} is reduced by Δt = 66.184 s to ΔT = 64.17 s. We believe the remaining difference ΔT is caused by the fact that T_{ref} as given by SanchisOjeda & Winn (2011) is reported to be in BJD_{TDB} but is actually BJD_{UTC}. In this case we would have to correct T_{ref} by adding Δt to convert it into BJD_{TDB}, and ΔT would reduce to approximately −2 s. This assumption is reasonable because SanchisOjeda & Winn published their paper in 2011, before the Kepler release notes 19 had been published; therefore, the problem of erroneous Kepler times was not yet known and the headers of the Kepler data files incorrectly stated that the times were in BJD_{TDB}^{2}.
Reference and revised ephemeris.
With this correction, the time shift of about one minute for early transit numbers in Fig. 1 virtually vanishes. Thus, we conclude that T_{ref} is most likely BJD_{UTC}; however, we have not changed this in Table 1 to be consistent with the table in SanchisOjeda & Winn (2011) from whence this value is taken.
We contacted Joshua Winn, who confirmed that this conclusion is plausible (Winn 2017, priv. comm.). When writing their paper SanchisOjeda & Winn (2011), they had no reason to suspect any problems with the Kepler time stamps.
References
 SanchisOjeda, R., & Winn, J. N. 2011, ApJ, 743, 61 [NASA ADS] [CrossRef] (In the text)
© ESO, 2017
All Tables
All Figures
Fig. 1
Measurements of midtransit times from 206Kepler transits. The (magenta) line represents a firstorder polynomial fit to the errorweighted measurements. The lower panel shows the residuals with outliers removed. See caption and text of original paper for more detailed explanations. 

Open with DEXTER  
In the text 