J23092+2439sdB

SDSSJ230913.64+243956.00 · 23:09:13.63 24:39:56.09 · 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]	26378 ± 188
log g	5.501 ± 0.031
log n(He)/n(H)	-1.937 ± 0.054
reduced χ²	0.977 over 640 points
radial velocity	36.0 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 19:11:01

Fit — uli

T_eff [K]	26609 ± 248
log g	5.415 ± 0.034
log n(He)/n(H)	-1.950 ± 0.054
reduced χ²	0.979 over 640 points
radial velocity	36.0 km s⁻¹
resolution (FWHM)	2.00 Å
lines fitted	12
grids	h909.grid h97.grid h99.grid h999.grid
fitted	04/09/2026 18:37:36

Observation

telescope	SDSS 2.5-M
survey / programme	boss
date	2013-09-01
exposure	5401 s in 12
pipeline	v5_13_2
S/N (classifier)	60.1
source file	spec-6589-56536-0934.fits

Gaia astrometry

Gaia DR3 source	2842756875183230976
parallax [mas]	0.3313 ± 0.0568
G	16.623
G_abs	4.288
μ_α [mas/yr]	1.803
μ_δ [mas/yr]	-10.572
l, b	95.189, -32.642

Published (Culpan et al. 2022)

class (Culpan)	sdB
class (SIMBAD)	sdB
T_eff [K]	26462 ± 849
log g	5.53 ± 0.11
log y	-2.00 ± 0.27
reference	2019MNRAS.486.2169K

Classifier

AGREES

fitted Teff 26462 logg 5.53 logY -2.0 2019MNRAS.486.2169K

auto: contrast 0.15, within the 0.32 a subdwarf reaches at 27 kK, Mg I b suggests a companion but Ca II does not (-1.3 sigma)

Fitted lines

line	λ [Å]	shift [Å]	continuum at	±avg	fitted over
H_β	4861.32	0.58	-40.0, 40.0	5.0	-45.0, 45.0
H_γ	4340.46	0.52	-40.0, 36.8	4.5	-43.0, 43.0
H_δ	4101.73	0.49	-40.0, 31.6	4.2	-43.0, 43.0
H_ε	3970.07	0.48	-28.0, 30.0	4.1	-30.0, 35.0
H_ζ	3889.05	0.47	-20.0, 26.2	4.0	-31.8, 32.0
H_η	3835.38	0.46	-20.0, 14.6	4.0	-20.7, 21.8
H_θ	3797.90	0.46	-16.0, 16.0	3.9	-15.6, 16.7
H_ι	3770.63	0.45	-13.0, 13.0	3.9	-11.7, 11.6
He II 4686	4685.70	0.56	-11.9, 11.9	4.9	-15.0, 13.8
He I 4472	4471.60	0.54	-15.0, 15.0	4.6	-15.0, 15.0
He I 4026	4026.29	0.48	-24.2, 15.0	4.2	-15.0, 15.0
He I 4922	4921.93	0.59	-15.0, 15.0	5.1	-15.0, 15.0

Spectral energy distribution

T_eff 26378 K · log g 5.501 · E(44−55) 0.162 · χ²_r 0.18 over 33 bands

distance 3018 pc · parallax 0.3300 ± 0.0600 mas (18%) · R 0.2549 +0.0530 −0.0373 R☉ · M 0.752 +0.366 −0.217 M☉ — above the 0.47 canonical mass · L 28.4 +13.0 −7.8 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.