J12564+2742sdB

PG1254+279 · 12:56:27.41 27:42:32.04 · 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.

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]	25632 ± 154
log g	5.717 ± 0.022
log n(He)/n(H)	-4.030 ± 0.349
reduced χ²	0.975 over 639 points
radial velocity	-20.0 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 19:08:54

Fit — uli

T_eff [K]	25687 ± 186
log g	5.623 ± 0.024
log n(He)/n(H)	-3.238 ± 0.073 upper limit
reduced χ²	0.973 over 639 points
radial velocity	-20.0 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 18:35:50

Observation

telescope	SDSS 2.5-M
survey / programme	boss
date	2013-02-11
exposure	6306 s in 14
pipeline	v5_13_2
S/N (classifier)	75.2
source file	spec-5972-56334-0639.fits

Gaia astrometry

Gaia DR3 source	1463697233542956672
parallax [mas]	0.5853 ± 0.0614
G	15.809
G_abs	4.693
μ_α [mas/yr]	-11.588
μ_δ [mas/yr]	-7.897
l, b	60.754, 88.744

Published (Culpan et al. 2022)

class (Culpan)	sdB
class (SIMBAD)	sdB
T_eff [K]	26180 ± 267
log g	5.57 ± 0.03
log y	-3.97 ± 0.11
reference	2021ApJS..256...28L

Classifier

AGREES

fitted Teff 26180 logg 5.57 logY -3.97 2021ApJS..256...28L

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 (0.0 sigma)

Fitted lines

line	λ [Å]	shift [Å]	continuum at	±avg	fitted over
H_β	4861.32	-0.32	-40.0, 40.0	5.0	-45.0, 45.0
H_γ	4340.46	-0.29	-40.0, 36.8	4.5	-43.0, 43.0
H_δ	4101.73	-0.27	-40.0, 31.6	4.2	-43.0, 43.0
H_ε	3970.07	-0.26	-28.0, 30.0	4.1	-30.0, 35.0
H_ζ	3889.05	-0.26	-20.0, 26.2	4.0	-31.8, 32.0
H_η	3835.38	-0.26	-20.0, 14.6	4.0	-20.7, 21.8
H_θ	3797.90	-0.25	-16.0, 16.0	3.9	-15.6, 16.7
H_ι	3770.63	-0.25	-13.0, 13.0	3.9	-11.7, 11.6
He II 4686	4685.70	-0.31	-11.9, 11.9	4.9	-15.0, 13.8
He I 4472	4471.60	-0.30	-15.0, 15.0	4.6	-15.0, 15.0
He I 4026	4026.29	-0.27	-24.2, 15.0	4.2	-15.0, 15.0
He I 4922	4921.93	-0.33	-15.0, 15.0	5.1	-15.0, 15.0

Spectral energy distribution

T_eff 25632 K · log g 5.717 · E(44−55) 0.016 · χ²_r 0.18 over 40 bands

distance 1709 pc · parallax 0.5900 ± 0.0600 mas (10%) · R 0.1758 +0.0207 −0.0167 R☉ · M 0.588 +0.169 −0.122 M☉ · L 12.0 +3.0 −2.2 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.