J16454+2051
PG1643+209 · Culpan knownhsd
χ²/N = 0.96
Spectrum
shaded: the intervals the fit used · │ a cancelled pixeldrag on either panel to zoom · dbl-click or Esc to reset · arrows to pan
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] | 26966 ± 128 |
| log g | 5.439 ± 0.020 |
| log n(He)/n(H) | -1.424 ± 0.039 |
| reduced χ² | 0.957 over 637 points |
| radial velocity | -148.0 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 19:09:46 |
Fit — uli
| Teff [K] | 27279 ± 183 |
| log g | 5.356 ± 0.025 |
| log n(He)/n(H) | -1.407 ± 0.051 |
| reduced χ² | 0.960 over 637 points |
| radial velocity | -148.0 km s−1 |
| resolution (FWHM) | 2.00 Å |
| lines fitted | 12 |
| grids | h909.grid h97.grid h99.grid h999.grid |
| fitted | 04/09/2026 18:36:33 |
Observation
| cosmic rays | 6 pixels cancelled |
| source file | spec-4183-55447-0972.fits |
Gaia astrometry
| Gaia DR3 source | 4564039545329170816 |
| parallax [mas] | 0.4141 ± 0.0428 |
| G | 15.816 |
| Gabs | 3.950 |
| μα [mas/yr] | -5.638 |
| μδ [mas/yr] | 0.868 |
| l, b | 39.677, 36.652 |
Published (Culpan et al. 2022)
| class (Culpan) | sdB |
| class (SIMBAD) | sdB |
| Teff [K] | 30200 ± 1000 |
| log g | 5.62 ± 0.15 |
| log y | -1.60 ± 0.10 |
| reference | 1994ApJ...432..351S |
Fitted lines
| line | λ [Å] | shift [Å] | continuum at | ±avg | fitted over |
| Hβ | 4861.32 | -2.40 | -40.0, 40.0 | 5.0 | -45.0, 45.0 |
| Hγ | 4340.46 | -2.14 | -40.0, 36.8 | 4.5 | -43.0, 43.0 |
| Hδ | 4101.73 | -2.02 | -40.0, 31.6 | 4.2 | -43.0, 43.0 |
| Hε | 3970.07 | -1.96 | -28.0, 30.0 | 4.1 | -30.0, 35.0 |
| Hζ | 3889.05 | -1.92 | -20.0, 26.2 | 4.0 | -31.8, 32.0 |
| Hη | 3835.38 | -1.89 | -20.0, 14.6 | 4.0 | -20.7, 21.8 |
| Hθ | 3797.90 | -1.87 | -16.0, 16.0 | 3.9 | -15.6, 16.7 |
| Hι | 3770.63 | -1.86 | -13.0, 13.0 | 3.9 | -11.7, 11.6 |
| He II 4686 | 4685.70 | -2.31 | -11.9, 11.9 | 4.9 | -15.0, 13.8 |
| He I 4472 | 4471.60 | -2.21 | -15.0, 15.0 | 4.6 | -15.0, 15.0 |
| He I 4026 | 4026.29 | -1.99 | -24.2, 15.0 | 4.2 | -15.0, 15.0 |
| He I 4922 | 4921.93 | -2.43 | -15.0, 15.0 | 5.1 | -15.0, 15.0 |
Spectral energy distribution
Teff 26966 K · log g 5.439 · E(44−55) 0.056 · χ²r 0.13 over 38 bands
distance 2415 pc · parallax 0.4100 ± 0.0400 mas (10%) · R 0.2487 +0.0289 −0.0234 R☉ · M 0.620 +0.177 −0.128 M☉ — above the 0.47 canonical mass · L 29.5 +7.3 −5.4 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.