J18431+4259
KIC7335517 · 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] | 48973 ± 1205 |
| log g | 5.746 ± 0.073 |
| log n(He)/n(H) | -2.400 ± 0.290 |
| reduced χ² | 0.978 over 637 points |
| radial velocity | -48.0 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 19:10:18 |
Fit — uli
| Teff [K] | 42789 ± 876 |
| log g | 5.608 ± 0.088 |
| log n(He)/n(H) | -2.507 ± 0.393 |
| reduced χ² | 0.961 over 637 points |
| radial velocity | -48.0 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 18:37:02 |
Observation
| cosmic rays | 4 pixels cancelled |
| source file | spec-104506-60562-63050395022831553.fits |
Gaia astrometry
| Gaia DR3 source | 2116808961511821312 |
| parallax [mas] | 0.4161 ± 0.0374 |
| G | 15.575 |
| Gabs | 3.663 |
| μα [mas/yr] | -0.592 |
| μδ [mas/yr] | -4.433 |
| l, b | 72.063, 19.545 |
Published (Culpan et al. 2022)
| class (Culpan) | sdB+WD |
| class (SIMBAD) | sdO+dM |
Fitted lines
| line | λ [Å] | shift [Å] | continuum at | ±avg | fitted over |
| Hβ | 4861.32 | -0.78 | -40.0, 40.0 | 5.0 | -45.0, 45.0 |
| Hγ | 4340.46 | -0.69 | -40.0, 36.8 | 4.5 | -43.0, 43.0 |
| Hδ | 4101.73 | -0.66 | -40.0, 31.6 | 4.2 | -43.0, 43.0 |
| Hε | 3970.07 | -0.64 | -28.0, 30.0 | 4.1 | -30.0, 35.0 |
| Hζ | 3889.05 | -0.62 | -20.0, 26.2 | 4.0 | -31.8, 32.0 |
| Hη | 3835.38 | -0.61 | -20.0, 14.6 | 4.0 | -20.7, 21.8 |
| Hθ | 3797.90 | -0.61 | -16.0, 16.0 | 3.9 | -15.6, 16.7 |
| Hι | 3770.63 | -0.60 | -13.0, 13.0 | 3.9 | -11.7, 11.6 |
| He II 4686 | 4685.70 | -0.75 | -11.9, 11.9 | 4.9 | -15.0, 13.8 |
| He I 4472 | 4471.60 | -0.72 | -15.0, 15.0 | 4.6 | -15.0, 15.0 |
| He I 4026 | 4026.29 | -0.64 | -24.2, 15.0 | 4.2 | -15.0, 15.0 |
| He I 4922 | 4921.93 | -0.79 | -15.0, 15.0 | 5.1 | -15.0, 15.0 |
Spectral energy distribution
Component 1, the subdwarf: Teff 48973 K (held) · log g 5.746 (held) · R 0.1706 R☉ (fitted, with the companion) · χ²r 0.82 over 38 bands
E(44−55) 0.070 (held)
Component 2, the companion: Teff 4000 K (fitted, 3500–8750 K grid) · log g 4.50 (held) · R 0.7329 R☉ (fitted) · χ²r 1.48 for the two components together (Δχ² 97 over one star, same bands)
The dashed curves beneath the model are the two components of this fit: the subdwarf alone and the cool companion.
distance 2403 pc · parallax 0.4200 ± 0.0400 mas (10%) · M 0.623 +0.156 −0.119 M☉ — above the 0.47 canonical mass · (from the ONE-star scale -- not corrected for the companion's light) · L 158.9 +33.4 −25.6 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.