J07483+4821sdB

SDSSJ074818.98+482107.7  ·  07:48:19.01 48:21:07.74  ·  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

profile fit on the Bamberg grid
Observed spectrum in black, model in red, offset by line. Balmer series left, helium right.

Line-profile fit — uli

profile fit on the uli grid
Observed spectrum in black, model in red, offset by line. Balmer series left, helium right.

Results and provenance

Fit — Bamberg

Teff [K]27556 ± 199
log g5.288 ± 0.029
log n(He)/n(H)-1.343 ± 0.039
reduced χ²0.974 over 637 points
radial velocity-79.0 km s−1
resolution (FWHM)2.00 Å
lines fitted12
gridsHE-0.041.fits
HE-0.125.fits
HE-0.300.fits
HE-0.550.fits
+9 more
fitted04/09/2026 19:07:41

Fit — uli

Teff [K]28098 ± 271
log g5.215 ± 0.034
log n(He)/n(H)-1.334 ± 0.049
reduced χ²0.960 over 637 points
radial velocity-79.0 km s−1
resolution (FWHM)2.00 Å
lines fitted12
gridsh667.grid
h909.grid
h97.grid
h99.grid
+1 more
fitted04/09/2026 18:34:50

Observation

telescopeSDSS 2.5-M
survey / programmeboss
date2010-02-20
exposure7203 s in 16
pipelinev5_13_2
S/N (classifier)68.0
source filespec-3665-55247-0953.fits

Gaia astrometry

Gaia DR3 source933799149409100160
parallax [mas]0.2729 ± 0.0535
G15.958
Gabs3.259
μα [mas/yr]-2.755
μδ [mas/yr]-2.562
l, b170.417, 29.079

Published (Culpan et al. 2022)

class (Culpan)sdB
class (SIMBAD)sdB1He13
Teff [K]27035 ± 1258
log g5.03 ± 0.19
log y-1.20 ± 0.20
reference2017OAst...26..164G

Classifier

AGREES

fitted Teff 27035 logg 5.03 logY -1.2 2017OAst...26..164G

auto: contrast 0.15, within the 0.30 a subdwarf reaches at 28 kK, Mg I b suggests a companion but Ca II does not (0.3 sigma)

Fitted lines

lineλ [Å]shift [Å]continuum at±avgfitted over
Hβ4861.32-1.28-40.0, 40.05.0-45.0, 45.0
Hγ4340.46-1.14-40.0, 36.84.5-43.0, 43.0
Hδ4101.73-1.08-40.0, 31.64.2-43.0, 43.0
Hε3970.07-1.05-28.0, 30.04.1-30.0, 35.0
Hζ3889.05-1.02-20.0, 26.24.0-31.8, 32.0
Hη3835.38-1.01-20.0, 14.64.0-20.7, 21.8
Hθ3797.90-1.00-16.0, 16.03.9-15.6, 16.7
Hι3770.63-0.99-13.0, 13.03.9-11.7, 11.6
He II 46864685.70-1.23-11.9, 11.94.9-15.0, 13.8
He I 44724471.60-1.18-15.0, 15.04.6-15.0, 15.0
He I 40264026.29-1.06-24.2, 15.04.2-15.0, 15.0
He I 49224921.93-1.30-15.0, 15.05.1-15.0, 15.0

Spectral energy distribution

Teff 27556 K · log g 5.288 · E(44−55) 0.086 · χ²r 0.37 over 37 bands

distance 3664 pc · parallax 0.2700 ± 0.0500 mas (19%) · R 0.3601 +0.0885 −0.0588 R☉ · M 0.921 +0.531 −0.290 M☉ — above the 0.47 canonical mass · L 67.5 +37.2 −20.4 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.