J07220+4032sdB

SDSSJ072201.31+403210.2 · 07:22:01.32 40:32:10.25 · 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]	27533 ± 216
log g	5.544 ± 0.035
log n(He)/n(H)	-2.813 ± 0.078
reduced χ²	0.996 over 637 points
radial velocity	-76.0 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 19:07:35

Fit — uli

T_eff [K]	27988 ± 283
log g	5.455 ± 0.037
log n(He)/n(H)	-2.833 ± 0.069
reduced χ²	0.998 over 637 points
radial velocity	-76.0 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 18:34:46

Observation

telescope	SDSS 2.5-M
survey / programme	boss
date	2010-02-14
exposure	4500 s in 10
pipeline	v5_13_2
S/N (classifier)	54.7
source file	spec-3656-55241-0356.fits

Gaia astrometry

Gaia DR3 source	948264290024452224
parallax [mas]	0.3288 ± 0.0503
G	16.296
G_abs	3.928
μ_α [mas/yr]	1.208
μ_δ [mas/yr]	-3.731
l, b	177.683, 22.728

Published (Culpan et al. 2022)

class (Culpan)	sdB
class (SIMBAD)	sdB

Classifier

AGREES

auto: contrast 0.11, within the 0.30 a subdwarf reaches at 27 kK, Ca II 8662/8542 = 7.5 -- the star's own Paschen lines, not a companion

Fitted lines

line	λ [Å]	shift [Å]	continuum at	±avg	fitted over
H_β	4861.32	-1.23	-40.0, 40.0	5.0	-45.0, 45.0
H_γ	4340.46	-1.10	-40.0, 36.8	4.5	-43.0, 43.0
H_δ	4101.73	-1.04	-40.0, 31.6	4.2	-43.0, 43.0
H_ε	3970.07	-1.01	-28.0, 30.0	4.1	-30.0, 35.0
H_ζ	3889.05	-0.99	-20.0, 26.2	4.0	-31.8, 32.0
H_η	3835.38	-0.97	-20.0, 14.6	4.0	-20.7, 21.8
H_θ	3797.90	-0.96	-16.0, 16.0	3.9	-15.6, 16.7
H_ι	3770.63	-0.96	-13.0, 13.0	3.9	-11.7, 11.6
He II 4686	4685.70	-1.19	-11.9, 11.9	4.9	-15.0, 13.8
He I 4472	4471.60	-1.13	-15.0, 15.0	4.6	-15.0, 15.0
He I 4026	4026.29	-1.02	-24.2, 15.0	4.2	-15.0, 15.0
He I 4922	4921.93	-1.25	-15.0, 15.0	5.1	-15.0, 15.0

Spectral energy distribution

T_eff 27533 K · log g 5.544 · E(44−55) 0.078 · χ²_r 0.14 over 33 bands

distance 3041 pc · parallax 0.3300 ± 0.0500 mas (15%) · R 0.2531 +0.0461 −0.0336 R☉ · M 0.820 +0.350 −0.220 M☉ — above the 0.47 canonical mass · L 33.2 +13.2 −8.3 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.