a detailed study with both a full pulsation analysis and dedicated spectroscopy
| reference | Ostensen et al. 2014, A&A 569, A15 |
| title | Asteroseismology revealing trapped modes in KIC 10553698A |
| Kepler data used | most of the mission at one-minute sampling |
| pulsations | 162 significant periodicities, 156 identified as l = 1 or 2 multiplet components; rotation period ~41 d; first clear indication of mode trapping in a stratified envelope |
| spectra behind it | ground-based spectroscopy giving a radial-velocity amplitude of 64.8 km/s; a 3.387 d photometric signal matches it in phase and amplitude as Doppler beaming |
| atmospheric parameters | Teff 27750 K, log g 5.45 (NLTE, tlusty/XTgrid), from the mean WHT spectrum after correcting for orbital velocity; S/N ~200 with many weak metal lines visible. VCS broadening instead of Tremblay & Bergeron lowers both by 800 K and 0.06 dex |
| earlier values | KepVI had 27600 / 5.33 from a single spectrum; superseded |
| the spectrum behind it | The orbit-corrected mean WHT spectrum the NLTE fit used is here as wht/kic10553698-meanallW-noOrbit.fits. |
| survey archive | A LAMOST DR11 spectrum exists and is here as LAMOST/, fitted in the LAMOST sample: 27504 +- 249 / 5.439 +- 0.040, which sits closer to the published 27750 / 5.45 than the WHT fit here does. |
| note | The companion KIC 10553698B is concluded to be a white dwarf. |
Paper: Ostensen14b.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 |
|---|---|---|---|---|---|---|---|---|---|---|
| LAMOST | LAMOST | 1 | 96.5 | 2.50 | 27504 ± 249 | 5.439 ± 0.040 | -2.67 ± 0.08 | 1.92% | 0.99 | |
| kpno | 1 | ? | ? | 27282 ± 61 | 5.514 ± 0.011 | -2.73 ± 0.03 | 0.79% | 1.98 | ||
| not | 1 | ? | ? | 26662 ± 82 | 5.512 ± 0.013 | -2.79 ± 0.04 | 1.11% | 2.24 | ||
| wht ★ | 1 | ? | ? | 27090 ± 34 | 5.532 ± 0.006 | -2.79 ± 0.02 | 0.63% | 3.16 |
★ 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] | 1277 |
| parallax error [%] | 3.4 (per cent; the mass error is twice this) |
| E(44−55) [mag] | 0.080 (0.070–0.092) |
| … the dust map | 0.1325 (SFD×disk(f=0.84)) |
| log Θ [rad] | -11.151 +0.006 −0.006 |
| R [R☉] | 0.200 +0.008 −0.007 |
| M [M☉] | 0.497 +0.073 −0.063 |
| L [L☉] | 19.4 +1.6 −1.5 |
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 27090 K and log g 5.532 from wht, with 36 of the fitted bands and reduced χ² 0.34. 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.