J08093+1608sdB
SDSSJ080921.96+160841.2 · 08:09:21.96 16:08:41.24 · Culpan knownhsd
χ²/N = 0.97
Spectrum
The whole reduced spectrum above, the region marked on it below. Shaded bands are the intervals the fit used; a tick under the axis marks a pixel the rejection mask cancelled.
Line-profile fit — Bamberg
Line-profile fit — uli
Results and provenance
Fit — Bamberg
| Teff [K] | 38833 ± 304 |
| log g | 5.787 ± 0.033 |
| log n(He)/n(H) | -3.193 ± 0.183 |
| reduced χ² | 0.971 over 639 points |
| radial velocity | -125.0 km s−1 |
| resolution (FWHM) | 2.00 Å |
| lines fitted | 12 |
| grids | HE-0.041.fits HE-0.125.fits HE-0.300.fits HE-0.550.fits +9 more |
| fitted | 04/09/2026 19:07:49 |
Fit — uli
| Teff [K] | 35863 ± 253 |
| log g | 5.661 ± 0.038 |
| log n(He)/n(H) | -3.332 ± 0.107 upper limit |
| reduced χ² | 0.934 over 639 points |
| radial velocity | -125.0 km s−1 |
| resolution (FWHM) | 2.00 Å |
| lines fitted | 12 |
| grids | h667.grid h909.grid h97.grid h99.grid +1 more |
| settled | outside the grid |
| fitted | 04/09/2026 18:34:55 |
Observation
| telescope | SDSS 2.5-M |
| survey / programme | boss |
| date | 2011-01-11 |
| exposure | 4504 s in 10 |
| pipeline | v5_13_2 |
| S/N (classifier) | 61.9 |
| source file | spec-4499-55572-0756.fits |
Gaia astrometry
| Gaia DR3 source | 656428099850193664 |
| parallax [mas] | 0.4140 ± 0.0447 |
| G | 15.716 |
| Gabs | 3.898 |
| μα [mas/yr] | -0.163 |
| μδ [mas/yr] | -4.908 |
| l, b | 206.543, 24.325 |
Published (Culpan et al. 2022)
| class (Culpan) | sdOB |
| class (SIMBAD) | sdO |
| Teff [K] | 36316 ± 967 |
| log g | 5.63 ± 0.13 |
| log y | -3.00 ± 0.20 |
| reference | 2017OAst...26..164G |
Classifier
DISPUTED
fitted Teff 36316 logg 5.63 logY -3.0 2017OAst...26..164G
auto: contrast 0.04, within the 0.22 a subdwarf reaches at 34 kK, Mg I b suggests a companion but Ca II does not (0.2 sigma)
Fitted lines
| line | λ [Å] | shift [Å] | continuum at | ±avg | fitted over |
| Hβ | 4861.32 | -2.03 | -40.0, 40.0 | 5.0 | -45.0, 45.0 |
| Hγ | 4340.46 | -1.81 | -40.0, 36.8 | 4.5 | -43.0, 43.0 |
| Hδ | 4101.73 | -1.71 | -40.0, 31.6 | 4.2 | -43.0, 43.0 |
| Hε | 3970.07 | -1.66 | -28.0, 30.0 | 4.1 | -30.0, 35.0 |
| Hζ | 3889.05 | -1.62 | -20.0, 26.2 | 4.0 | -31.8, 32.0 |
| Hη | 3835.38 | -1.60 | -20.0, 14.6 | 4.0 | -20.7, 21.8 |
| Hθ | 3797.90 | -1.58 | -16.0, 16.0 | 3.9 | -15.6, 16.7 |
| Hι | 3770.63 | -1.57 | -13.0, 13.0 | 3.9 | -11.7, 11.6 |
| He II 4686 | 4685.70 | -1.95 | -11.9, 11.9 | 4.9 | -15.0, 13.8 |
| He I 4472 | 4471.60 | -1.86 | -15.0, 15.0 | 4.6 | -15.0, 15.0 |
| He I 4026 | 4026.29 | -1.68 | -24.2, 15.0 | 4.2 | -15.0, 15.0 |
| He I 4922 | 4921.93 | -2.05 | -15.0, 15.0 | 5.1 | -15.0, 15.0 |
Spectral energy distribution
Teff 38833 K · log g 5.787 · E(44−55) 0.044 · χ²r 0.21 over 37 bands
distance 2415 pc · parallax 0.4100 ± 0.0400 mas (10%) · R 0.1848 +0.0225 −0.0181 R☉ · M 0.763 +0.227 −0.162 M☉ — above the 0.47 canonical mass · L 70.0 +18.1 −13.2 L☉
Photometry against the model, with the residual beneath it in units of the error. The horizontal bar on each point is the passband, not an error; a hollow point was not fitted and the tooltip says why. Drag a box to zoom, double-click or Esc to come back out.