published, but the study is early or one-sided: only part of the Kepler data, or no spectroscopy of its own
The published spectrum is not on disk here. The Nature paper's spectroscopy is MMT. Only a KPNO 4m mean and a Bok mean are here. The MMT spectra have not been found on disk -- ask S. Charpinet or E. M. Green.
| reference | Charpinet et al. 2011, Nature 480, 496 |
| title | A compact system of small planets around a former red-giant star |
| Kepler data used | (not stated in the part read here) |
| pulsations | Two nearly Earth-sized bodies inferred around the post-red-giant hot subdwarf KIC 05807616 |
| spectra behind it | MMT spectra were obtained for KIC 05807616 |
| atmospheric parameters | the supplement gives Teff 27730 +- 270 K and L = 22.9 +- 3.1 Lsun; a log g was not found in the copy here |
| the spectrum behind it | The Nature paper's spectroscopy is MMT. Only a KPNO 4m mean and a Bok mean are here. The MMT spectra have not been found on disk -- ask S. Charpinet or E. M. Green. |
| note | A Nature Letter about the planetary bodies rather than a spectroscopic study of the star. A supplementary information file (Charpinet11bs.pdf) accompanies it. |
Paper: Charpinet11b.pdf, in /home/roy/sync/old/sddoc.
| observation | telescope | date | n | S/N | FWHM [Å] | Teff [K] | log g | log n(He)/n(H) | residual | χ² |
|---|---|---|---|---|---|---|---|---|---|---|
| BOK ★ | bok / Bok B&C Spectrograph | 2008-09-20 | 1 | 439.8 | 9.00 | 26953 ± 74 | 5.549 ± 0.014 | -2.79 ± 0.03 | 1.34% | 6.32 |
| KPNO | kp4m / test | 2010-08-13 | 5 | 151.2 | 1.56 | 27149 ± 116 | 5.439 ± 0.020 | -2.71 ± 0.04 | 1.65% | 2.45 |
★ marks the observation adopted for the sample table — the one with the smallest residual, which is what says how well the model reproduces the spectrum. Signal-to-noise does not.
The line fit gives a temperature and a gravity but says nothing about size. Held at those parameters, the broadband spectral energy distribution has one free scale — the angular diameter — and the Gaia parallax turns that into a radius. Then M = gR²/G, which is linear in g: a tenth of a dex in gravity is 26 per cent in mass, so this is where the gravity scale bites hardest.
| distance [pc] | 1090 |
| parallax error [%] | 2.7 (per cent; the mass error is twice this) |
| E(44−55) [mag] | 0.084 (0.076–0.094) |
| … the dust map | 0.1518 (SFD×disk(f=0.72)) |
| log Θ [rad] | -11.128 +0.005 −0.005 |
| R [R☉] | 0.180 +0.005 −0.005 |
| M [M☉] | 0.418 +0.058 −0.051 |
| L [L☉] | 15.4 +1.1 −1.0 |
Bamberg v25 ATLAS12 through the real filter curves, reddened by Fitzpatrick (1999) — its A(5500)/E(B−V) is 3.03, so this E(B−V) and the E(44−55) of Heber's group are the same number to under one per cent. Prescribed at 26953 K and log g 5.549 from BOK, with 36 of the fitted bands and reduced χ² 0.41. The gravity error carried into the mass is 0.050 dex — the scatter between telescopes, not the formal error, because the formal one would claim a two per cent mass.
Bands left out: Johnson:B, GALEX:NUV, GALEX:FUV, 2MASS:H, 2MASS:Ks, WISE:W3, WISE:W4, GAIA/GAIA3:G, GAIA/GAIA3:Gbp, GAIA/GAIA3:Grp, SDSS:u, SDSS:g, SDSS:r, SDSS:i, SDSS:z, SDSS:u/SDSS:u', SDSS:g/SDSS:g', SDSS:r/SDSS:r', SDSS:i/SDSS:i', SDSS:z/SDSS:z', Johnson:U, Johnson:V, Cousins:U.
kpno/ and kpd/ are copies of the original fitprof22 working directories from data/spek/kepler (kpno/kic05807616 and KepI/KPD1943+4058), kept as they were run, with the line lists of their own era. The live directories are KPNO/ and BOK/, linked to the master. kpno/ arrived holding its spectrum as sp.spek, which is the name fitk1 looks for, so the archive copy was being fitted on its own 2012 line list. The file is renamed kpno.spek here and its runfit20.dat points at the new name, so the 2012 fit is still reproducible and the directory is an archive again. The original at data/spek/kepler/kpno/kic05807616 is untouched. The two headers disagree on where the star is: KPNO gives 19:45:48.2 +41:07:30, Bok gives 19:45:25.5 +41:05:35, about 5 arcmin apart. The two fits agree to 200 K, so it is the same star and one header is a pointing rather than a position -- worth settling before either is used for astrometry or cross-matching.