J10389+5258sdB

SDSSJ103854.02+525847.8 · 10:38:54.02 52:58:47.86 · Culpan knownhsd

χ²/N = 0.98

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

Observed spectrum in black, model in red, offset by line. Balmer series left, helium right.

Line-profile fit — uli

Observed spectrum in black, model in red, offset by line. Balmer series left, helium right.

Results and provenance

Fit — Bamberg

T_eff [K]	26614 ± 212
log g	5.529 ± 0.032
log n(He)/n(H)	-3.196 ± 0.172
reduced χ²	0.979 over 637 points
radial velocity	-151.0 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 19:08:25

Fit — uli

T_eff [K]	26861 ± 282
log g	5.434 ± 0.036
log n(He)/n(H)	-3.084 ± 0.076 upper limit
reduced χ²	0.975 over 637 points
radial velocity	-151.0 km s⁻¹
resolution (FWHM)	2.00 Å
lines fitted	12
grids	h909.grid h97.grid h99.grid h999.grid
settled	outside the grid
fitted	04/09/2026 18:35:25

Observation

telescope	SDSS 2.5-M
survey / programme	boss
date	2013-12-10
exposure	7201 s in 16
pipeline	v5_13_2
S/N (classifier)	69.4
source file	spec-6703-56636-0530.fits

Gaia astrometry

Gaia DR3 source	849277216680457600
parallax [mas]	0.3984 ± 0.0539
G	16.162
G_abs	4.168
μ_α [mas/yr]	-5.948
μ_δ [mas/yr]	-3.105
l, b	157.330, 54.369

Published (Culpan et al. 2022)

class (Culpan)	sdB
class (SIMBAD)	DA1:
T_eff [K]	26127 ± 1191
log g	5.31 ± 0.17
log y	-2.70 ± 0.20
reference	2017OAst...26..164G

Classifier

AGREES

fitted Teff 26127 logg 5.31 logY -2.7 2017OAst...26..164G

auto: contrast 0.14, within the 0.32 a subdwarf reaches at 26 kK, Mg I b suggests a companion but Ca II does not (-1.8 sigma)

Fitted lines

line	λ [Å]	shift [Å]	continuum at	±avg	fitted over
H_β	4861.32	-2.45	-40.0, 40.0	5.0	-45.0, 45.0
H_γ	4340.46	-2.19	-40.0, 36.8	4.5	-43.0, 43.0
H_δ	4101.73	-2.07	-40.0, 31.6	4.2	-43.0, 43.0
H_ε	3970.07	-2.00	-28.0, 30.0	4.1	-30.0, 35.0
H_ζ	3889.05	-1.96	-20.0, 26.2	4.0	-31.8, 32.0
H_η	3835.38	-1.93	-20.0, 14.6	4.0	-20.7, 21.8
H_θ	3797.90	-1.91	-16.0, 16.0	3.9	-15.6, 16.7
H_ι	3770.63	-1.90	-13.0, 13.0	3.9	-11.7, 11.6
He II 4686	4685.70	-2.36	-11.9, 11.9	4.9	-15.0, 13.8
He I 4472	4471.60	-2.25	-15.0, 15.0	4.6	-15.0, 15.0
He I 4026	4026.29	-2.03	-24.2, 15.0	4.2	-15.0, 15.0
He I 4922	4921.93	-2.48	-15.0, 15.0	5.1	-15.0, 15.0

Spectral energy distribution

T_eff 26614 K · log g 5.529 · E(44−55) 0.018 · χ²_r 0.10 over 37 bands

distance 2510 pc · parallax 0.4000 ± 0.0500 mas (12%) · R 0.2116 +0.0333 −0.0252 R☉ · M 0.554 +0.205 −0.137 M☉ · L 20.3 +6.9 −4.6 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.