J20463+0626sdB

HS2043+0615 · 20:46:20.78 06:26:25.33 · Culpan knownhsd

χ²/N = 1.00

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]	27603 ± 398
log g	5.339 ± 0.064
log n(He)/n(H)	-2.413 ± 0.133
reduced χ²	0.996 over 637 points
radial velocity	24.0 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 19:10:34

Fit — uli

T_eff [K]	27951 ± 497
log g	5.240 ± 0.064
log n(He)/n(H)	-2.405 ± 0.150
reduced χ²	0.997 over 637 points
radial velocity	24.0 km s⁻¹
resolution (FWHM)	2.00 Å
lines fitted	12
grids	h667.grid h909.grid h97.grid h99.grid +1 more
fitted	04/09/2026 18:37:15

Observation

telescope	SDSS 2.5-M
survey / programme	MWM / mwm_cb
field · MJD	101033 · 60123
date	2023-06-28
catalogid	27021598875665729
exposure	900 s in 1
airmass	1.11
seeing (50%)	1.43″
E(B−V)	0.086
pipeline	v6_2_1
S/N (classifier)	24.4
source file	spec-101033-60123-27021598875665729.fits

Gaia astrometry

Gaia DR3 source	1735991253803944960
parallax [mas]	0.3316 ± 0.0435
G	15.921
BP − RP	-0.318
G_abs	3.641
μ_α [mas/yr]	-2.774
μ_δ [mas/yr]	-6.306
l, b	52.958, -21.957

Published (Culpan et al. 2022)

class (Culpan)	sdB+dM
class (SIMBAD)	sdB
T_eff [K]	26157 ± 500
log g	5.28 ± 0.05
log y	-2.38 ± 0.05
reference	2005A&A...430..223L

Classifier

AGREES

fitted Teff 26157 logg 5.28 logY -2.38 2005A&A...430..223L

auto: contrast 0.16, within the 0.30 a subdwarf reaches at 28 kK, Mg I b suggests a companion but Ca II does not (-0.6 sigma)

Fitted lines

line	λ [Å]	shift [Å]	continuum at	±avg	fitted over
H_β	4861.32	0.39	-40.0, 40.0	5.0	-45.0, 45.0
H_γ	4340.46	0.35	-40.0, 36.8	4.5	-43.0, 43.0
H_δ	4101.73	0.33	-40.0, 31.6	4.2	-43.0, 43.0
H_ε	3970.07	0.32	-28.0, 30.0	4.1	-30.0, 35.0
H_ζ	3889.05	0.31	-20.0, 26.2	4.0	-31.8, 32.0
H_η	3835.38	0.31	-20.0, 14.6	4.0	-20.7, 21.8
H_θ	3797.90	0.30	-16.0, 16.0	3.9	-15.6, 16.7
H_ι	3770.63	0.30	-13.0, 13.0	3.9	-11.7, 11.6
He II 4686	4685.70	0.38	-11.9, 11.9	4.9	-15.0, 13.8
He I 4472	4471.60	0.36	-15.0, 15.0	4.6	-15.0, 15.0
He I 4026	4026.29	0.32	-24.2, 15.0	4.2	-15.0, 15.0
He I 4922	4921.93	0.39	-15.0, 15.0	5.1	-15.0, 15.0

Spectral energy distribution

T_eff 27603 K · log g 5.339 · E(44−55) 0.098 · χ²_r 0.41 over 35 bands

distance 3016 pc · parallax 0.3300 ± 0.0400 mas (12%) · R 0.3064 +0.0465 −0.0357 R☉ · M 0.749 +0.271 −0.181 M☉ — above the 0.47 canonical mass · L 49.1 +16.1 −10.9 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.