J15175+2259sdB
PG1515+232 · 15:17:33.34 22:59:08.16 · Culpan knownhsd
χ²/N = 0.98
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] | 26766 ± 146 |
| log g | 5.536 ± 0.025 |
| log n(He)/n(H) | -2.553 ± 0.087 |
| reduced χ² | 0.981 over 639 points |
| radial velocity | -19.0 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 19:09:20 |
Fit — uli
| Teff [K] | 26995 ± 188 |
| log g | 5.441 ± 0.026 |
| log n(He)/n(H) | -2.585 ± 0.086 |
| reduced χ² | 0.981 over 639 points |
| radial velocity | -19.0 km s−1 |
| resolution (FWHM) | 2.00 Å |
| lines fitted | 12 |
| grids | h909.grid h97.grid h99.grid h999.grid |
| fitted | 04/09/2026 18:36:11 |
Observation
| telescope | SDSS 2.5-M |
| survey / programme | boss |
| date | 2011-04-27 |
| exposure | 9008 s in 20 |
| pipeline | v5_13_2 |
| S/N (classifier) | 66.9 |
| source file | spec-3955-55678-0598.fits |
Gaia astrometry
| Gaia DR3 source | 1215384730117100032 |
| parallax [mas] | 0.3505 ± 0.0628 |
| G | 16.443 |
| Gabs | 4.221 |
| μα [mas/yr] | -6.487 |
| μδ [mas/yr] | -5.494 |
| l, b | 34.001, 56.765 |
Published (Culpan et al. 2022)
| class (Culpan) | sdB |
| class (SIMBAD) | sdB |
| Teff [K] | 27772 ± 547 |
| log g | 5.80 ± 0.08 |
| log y | -2.89 ± 0.20 |
| reference | 2021ApJS..256...28L |
Classifier
AGREES
fitted Teff 27772 logg 5.8 logY -2.89 2021ApJS..256...28L
auto: contrast 0.13, within the 0.32 a subdwarf reaches at 27 kK, Ca II 8662/8542 = 7.4 -- the star's own Paschen lines, not a companion
Fitted lines
| line | λ [Å] | shift [Å] | continuum at | ±avg | fitted over |
| Hβ | 4861.32 | -0.31 | -40.0, 40.0 | 5.0 | -45.0, 45.0 |
| Hγ | 4340.46 | -0.28 | -40.0, 36.8 | 4.5 | -43.0, 43.0 |
| Hδ | 4101.73 | -0.26 | -40.0, 31.6 | 4.2 | -43.0, 43.0 |
| Hε | 3970.07 | -0.25 | -28.0, 30.0 | 4.1 | -30.0, 35.0 |
| Hζ | 3889.05 | -0.25 | -20.0, 26.2 | 4.0 | -31.8, 32.0 |
| Hη | 3835.38 | -0.24 | -20.0, 14.6 | 4.0 | -20.7, 21.8 |
| Hθ | 3797.90 | -0.24 | -16.0, 16.0 | 3.9 | -15.6, 16.7 |
| Hι | 3770.63 | -0.24 | -13.0, 13.0 | 3.9 | -11.7, 11.6 |
| He II 4686 | 4685.70 | -0.30 | -11.9, 11.9 | 4.9 | -15.0, 13.8 |
| He I 4472 | 4471.60 | -0.28 | -15.0, 15.0 | 4.6 | -15.0, 15.0 |
| He I 4026 | 4026.29 | -0.26 | -24.2, 15.0 | 4.2 | -15.0, 15.0 |
| He I 4922 | 4921.93 | -0.31 | -15.0, 15.0 | 5.1 | -15.0, 15.0 |
Spectral energy distribution
Teff 26766 K · log g 5.536 · E(44−55) 0.048 · χ²r 0.13 over 30 bands
distance 2853 pc · parallax 0.3500 ± 0.0600 mas (17%) · R 0.2209 +0.0485 −0.0336 R☉ · M 0.613 +0.316 −0.182 M☉ · L 22.6 +11.0 −6.4 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.