J22210-4157sdO

GALEXJ22210-4157 · 22:21:05.16 -41:57:42.16 · Culpan knownhsd

χ²/N = 0.92

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]	47289 ± 854
log g	6.293 ± 0.086
log n(He)/n(H)	-1.511 ± 0.110
reduced χ²	0.917 over 745 points
radial velocity	-21.0 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 19:10:52

Observation

telescope	LCO Du Pont
survey / programme	MWM / mwm_halo
field · MJD	108557 · 60568
date	2024-09-15
catalogid	63050396479037208
exposure	900 s in 1
airmass	1.03
seeing (50%)	0.97″
E(B−V)	0.012
pipeline	v6_2_1
S/N (classifier)	30.1
source file	spec-108557-60568-63050396479037208.fits

Gaia astrometry

Gaia DR3 source	6569423959823272960
parallax [mas]	0.8083 ± 0.0431
G	14.831
BP − RP	-0.528
G_abs	4.425
μ_α [mas/yr]	35.010
μ_δ [mas/yr]	-14.792
l, b	357.193, -56.027

Published (Culpan et al. 2022)

class (Culpan)	sdO
class (SIMBAD)	sdO

Classifier

AGREES

auto: He II/He I 7.5, EW 1.13, Mg I b suggests a companion but Ca II does not (-1.6 sigma); contrast 0.06 over the 0.04 expected at 54 kK

Fitted lines

line	λ [Å]	shift [Å]	continuum at	±avg	fitted over
H_β	4861.32	-0.34	-40.0, 40.0	5.0	-45.0, 45.0
H_γ	4340.46	-0.30	-40.0, 36.8	4.5	-43.0, 43.0
H_δ	4101.73	-0.29	-40.0, 31.6	4.2	-43.0, 43.0
H_ε	3970.07	-0.28	-28.0, 30.0	4.1	-30.0, 35.0
H_ζ	3889.05	-0.27	-20.0, 26.2	4.0	-31.8, 32.0
H_η	3835.38	-0.27	-20.0, 14.6	4.0	-20.7, 21.8
H_θ	3797.90	-0.27	-16.0, 16.0	3.9	-15.6, 16.7
H_ι	3770.63	-0.26	-13.0, 13.0	3.9	-11.7, 11.6
He II 4686	4685.70	-0.33	-11.9, 11.9	4.9	-15.0, 13.8
He II 5412	5411.52	-0.38	-15.0, 15.0	5.6	-15.0, 15.0
He II 4542	4541.59	-0.32	-15.0, 20.0	4.7	-20.0, 20.0
He II 4200	4199.84	-0.29	-23.5, 33.8	4.3	-20.0, 20.0
He I 4472	4471.60	-0.31	-15.0, 15.0	4.6	-15.0, 15.0
He I 4026	4026.29	-0.28	-24.2, 15.0	4.2	-15.0, 15.0
He I 4922	4921.93	-0.34	-15.0, 15.0	5.1	-15.0, 15.0

Spectral energy distribution

T_eff 47289 K · log g 6.293 · E(44−55) 0.008 · χ²_r 0.14 over 41 bands

distance 1237 pc · parallax 0.8100 ± 0.0400 mas (5%) · R 0.1185 +0.0068 −0.0060 R☉ · M 1.007 +0.173 −0.148 M☉ — above the 0.47 canonical mass · L 63.3 +7.5 −6.4 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.