published, but the study is early or one-sided: only part of the Kepler data, or no spectroscopy of its own
| reference | Reed et al. 2012, MNRAS 427, 1245 |
| title | The discovery of two pulsating subdwarf B stars in NGC 6791 using Kepler |
| Kepler data used | one month of short cadence, one star per month |
| atmospheric parameters | B5 = KIC 2437937, Kp 17.978, Teff 23844 +- 676 K, log g 5.31 +- 0.09, log N(He)/N(H) -2.71 +- 0.22 |
| the spectrum behind it | Reed et al. obtained ALFOSC spectra at the NOT in 2012 May; the B5 extraction from that run is here. |
| as a reference object | no At Kp ~18 in a crowded cluster field these are the faintest stars in the project; the spectra reach S/N 27-55 and are not good reference objects for spectroscopy. They are here for completeness. |
| note | A discovery paper on one month of data. The 24786 K in the target list is B4's value, not B5's -- the two rows carried the same number. |
Paper: Reed12b.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 |
|---|---|---|---|---|---|---|---|---|---|---|
| NOT ★ | NOT / ALFOSC_FASU | 2012-05-17 | 1 | 32.6 | 4.50 | 24094 ± 632 | 5.479 ± 0.083 | -2.95 ± 0.34 | 4.41% | 1.12 |
★ 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.
No SED fit is published for this star — see below for why. The photometry is on disk as sed/phot.csv either way.
| note | No SED fit. One of the three NGC 6791 cluster members here, and the cluster is the problem: at V = 18.4 in a dense field the merged photometry gives u = 21.3 against G = 18.3, three magnitudes of disagreement that no reddening can absorb, and the fit reaches a reduced chi-square of 12. Adamanta and Fredegar are in the same cluster; Fredegar is fitted but flagged, Adamanta only survives because its parallax is so poor that nothing else shows. |
The lower-case directories (b3/, b3-1/, b3-2/, b4/, b5/) are copies of the 2012 fitprof22 working directories from data/spek/NGC6791, kept as they were run, each with the line list of its own era. None holds an sp.spek, so fitk1 does not read them. The live directories are NOT/ (and NOT-1/, NOT-2/ for Fredegar), extracted from the same FITS and linked to the master. All five spectra are NOT/ALFOSC Grism #16 through a 1.0in slit, so they share one resolution: 4.50 A, the value the 2012 fits used. Ca II K cannot supply it here -- at S/N 25-55 the line is only 6-16% deep and its measured width scatters from 1.9 to 4.1 A between spectra of the same field. Two stars share each slit: b3b6 (Fredegar and B6) and b4b5 (Adamanta and Adelard). The header RA/DEC is the slit centre, not the star, and B6 is not one of the nineteen -- its spectra stay in data/spek/NGC6791.