J17309+3207sdB
SDSSJ173057.94+320737.0 · 17:30:57.94 32:07:37.09 · Culpan knownhsd
χ²/N = 1.01
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] | 27262 ± 152 |
| log g | 5.527 ± 0.025 |
| log n(He)/n(H) | -2.793 ± 0.081 |
| reduced χ² | 1.010 over 636 points |
| radial velocity | -181.0 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 19:10:01 |
Fit — uli
| Teff [K] | 27665 ± 209 |
| log g | 5.435 ± 0.027 |
| log n(He)/n(H) | -2.821 ± 0.075 |
| reduced χ² | 1.007 over 636 points |
| radial velocity | -181.0 km s−1 |
| resolution (FWHM) | 2.00 Å |
| lines fitted | 12 |
| grids | h667.grid h909.grid h97.grid h99.grid +1 more |
| fitted | 04/09/2026 18:36:45 |
Observation
| telescope | SDSS 2.5-M |
| survey / programme | boss |
| date | 2011-05-29 |
| exposure | 4504 s in 10 |
| pipeline | v5_13_2 |
| S/N (classifier) | 60.2 |
| source file | spec-5002-55710-0887.fits |
Gaia astrometry
| Gaia DR3 source | 4601638307512889088 |
| parallax [mas] | 0.3932 ± 0.0435 |
| G | 16.146 |
| Gabs | 4.111 |
| μα [mas/yr] | -4.391 |
| μδ [mas/yr] | -7.194 |
| l, b | 56.110, 30.115 |
Published (Culpan et al. 2022)
| class (Culpan) | sdB |
| class (SIMBAD) | sdB |
| Teff [K] | 28200 ± 700 |
| log g | 5.40 ± 0.05 |
| log y | -2.90 ± 0.20 |
| reference | 2015A&A...577A..26G |
Classifier
AGREES
fitted Teff 28200 logg 5.4 logY -2.9 2015A&A...577A..26G
auto: contrast 0.14, within the 0.29 a subdwarf reaches at 28 kK, Ca II 8662/8542 = 4.0 -- the star's own Paschen lines, not a companion
Fitted lines
| line | λ [Å] | shift [Å] | continuum at | ±avg | fitted over |
| Hβ | 4861.32 | -2.94 | -40.0, 40.0 | 5.0 | -45.0, 45.0 |
| Hγ | 4340.46 | -2.62 | -40.0, 36.8 | 4.5 | -43.0, 43.0 |
| Hδ | 4101.73 | -2.48 | -40.0, 31.6 | 4.2 | -43.0, 43.0 |
| Hε | 3970.07 | -2.40 | -28.0, 30.0 | 4.1 | -30.0, 35.0 |
| Hζ | 3889.05 | -2.35 | -20.0, 26.2 | 4.0 | -31.8, 32.0 |
| Hη | 3835.38 | -2.32 | -20.0, 14.6 | 4.0 | -20.7, 21.8 |
| Hθ | 3797.90 | -2.29 | -16.0, 16.0 | 3.9 | -15.6, 16.7 |
| Hι | 3770.63 | -2.28 | -13.0, 13.0 | 3.9 | -11.7, 11.6 |
| He II 4686 | 4685.70 | -2.83 | -11.9, 11.9 | 4.9 | -15.0, 13.8 |
| He I 4472 | 4471.60 | -2.70 | -15.0, 15.0 | 4.6 | -15.0, 15.0 |
| He I 4026 | 4026.29 | -2.43 | -24.2, 15.0 | 4.2 | -15.0, 15.0 |
| He I 4922 | 4921.93 | -2.97 | -15.0, 15.0 | 5.1 | -15.0, 15.0 |
Spectral energy distribution
Teff 27262 K · log g 5.527 · E(44−55) 0.036 · χ²r 0.27 over 36 bands
distance 2543 pc · parallax 0.3900 ± 0.0400 mas (10%) · R 0.2154 +0.0270 −0.0216 R☉ · M 0.571 +0.174 −0.123 M☉ · L 23.1 +6.2 −4.5 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.