J10039+4034sdO

PG1000+408 · 10:03:54.26 40:34:18.12 · Culpan knownhsd

χ²/N = 0.97

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.

Results and provenance

Fit — Bamberg

T_eff [K]	41271 ± 315
log g	5.710 ± 0.033
log n(He)/n(H)	-2.623 ± 0.166
reduced χ²	0.975 over 743 points
radial velocity	-86.0 km s⁻¹
resolution (FWHM)	2.00 Å
lines fitted	15
grids	HE-0.041.fits HE-0.125.fits HE-0.300.fits HE-0.550.fits +9 more
fitted	04/09/2026 19:08:15

Observation

telescope	SDSS 2.5-M
survey / programme	COMMISSIONING / commissioning
field · MJD	020925 · 60007
date	2023-03-04
catalogid	27021598153987647
exposure	600 s in 2
airmass	1.12
seeing (50%)	1.60″
E(B−V)	0.012
pipeline	v6_2_1
cosmic rays	4 pixels cancelled
S/N (classifier)	43.4
source file	spec-020925-60007-27021598153987647.fits

Gaia astrometry

Gaia DR3 source	803736166614876544
parallax [mas]	0.9993 ± 0.0365
G	13.250
BP − RP	-0.590
G_abs	3.294
μ_α [mas/yr]	-2.294
μ_δ [mas/yr]	-19.272
l, b	180.600, 53.118

Published (Culpan et al. 2022)

class (Culpan)	sdB+WD
class (SIMBAD)	sdO
T_eff [K]	36400 ± 1000
log g	5.54 ± 0.10
log y	-2.70 ± 0.10
reference	2001MNRAS.326.1391M

Classifier

DISPUTED

fitted Teff 36400 logg 5.54 logY -2.7 2001MNRAS.326.1391M

auto: He II/He I 3.2, EW 0.48, Mg I b suggests a companion but Ca II does not (0.9 sigma)

Fitted lines

line	λ [Å]	shift [Å]	continuum at	±avg	fitted over
H_β	4861.32	-1.39	-40.0, 40.0	5.0	-45.0, 45.0
H_γ	4340.46	-1.25	-40.0, 36.8	4.5	-43.0, 43.0
H_δ	4101.73	-1.18	-40.0, 31.6	4.2	-43.0, 43.0
H_ε	3970.07	-1.14	-28.0, 30.0	4.1	-30.0, 35.0
H_ζ	3889.05	-1.12	-20.0, 26.2	4.0	-31.8, 32.0
H_η	3835.38	-1.10	-20.0, 14.6	4.0	-20.7, 21.8
H_θ	3797.90	-1.09	-16.0, 16.0	3.9	-15.6, 16.7
H_ι	3770.63	-1.08	-13.0, 13.0	3.9	-11.7, 11.6
He II 4686	4685.70	-1.34	-11.9, 11.9	4.9	-15.0, 13.8
He II 5412	5411.52	-1.55	-15.0, 15.0	5.6	-15.0, 15.0
He II 4542	4541.59	-1.30	-15.0, 20.0	4.7	-20.0, 20.0
He II 4200	4199.84	-1.20	-23.5, 33.8	4.3	-20.0, 20.0
He I 4472	4471.60	-1.28	-15.0, 15.0	4.6	-15.0, 15.0
He I 4026	4026.29	-1.16	-24.2, 15.0	4.2	-15.0, 15.0
He I 4922	4921.93	-1.41	-15.0, 15.0	5.1	-15.0, 15.0

Spectral energy distribution

T_eff 41271 K · log g 5.710 · E(44−55) 0.008 · χ²_r 0.11 over 38 bands

distance 1001 pc · parallax 1.0000 ± 0.0400 mas (4%) · R 0.2165 +0.0084 −0.0077 R☉ · M 0.877 +0.130 −0.112 M☉ — above the 0.47 canonical mass · L 122.5 +10.0 −9.0 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.