J16499+5331

PG1648+536 · Culpan knownhsd

outside the grid 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.

Results and provenance

Fit — Bamberg

T_eff [K]	31661 ± 210
log g	5.606 ± 0.027
log n(He)/n(H)	-6.118 ± 0.696 upper limit
reduced χ²	0.972 over 639 points
radial velocity	83.0 km s⁻¹
resolution (FWHM)	2.50 Å
lines fitted	12
grids	HE-0.041.fits HE-0.125.fits HE-0.300.fits HE-0.550.fits +9 more
settled	outside the grid
fitted	04/09/2026 18:32:19

Fit — Lei (TLUSTY)

T_eff [K]	31000 ± 740
log g	5.600 ± 0.120
log n(He)/n(H)	-3.000 ± 0.000
grids	Lei et al. 2018, ApJ 868, 70 SYNSPEC 49 spectra from NLTE TLUSTY 204 model atmospheres, through XTgrid
helium	published as a limit

Observation

source file

spec-57879-HD165618N524154B02_sp15-067.fits.gz

Gaia astrometry

Gaia DR3 source	1425987175870116864
parallax [mas]	1.1718 ± 0.0248
G	14.009
G_abs	4.366
μ_α [mas/yr]	-1.278
μ_δ [mas/yr]	-22.011
l, b	81.377, 39.351

Published (Culpan et al. 2022)

class (Culpan)	sdB+WD
class (SIMBAD)	sdB1VIIHe0
T_eff [K]	33698 ± 148
log g	5.75 ± 0.03
log y	-3.47 ± 0.07
reference	2021ApJS..256...28L

Fitted lines

line	λ [Å]	shift [Å]	continuum at	±avg	fitted over
H_β	4861.32	1.35	-40.0, 40.0	5.0	-45.0, 45.0
H_γ	4340.46	1.20	-40.0, 36.8	4.5	-43.0, 43.0
H_δ	4101.73	1.14	-40.0, 31.6	4.2	-43.0, 43.0
H_ε	3970.07	1.10	-28.0, 30.0	4.1	-30.0, 35.0
H_ζ	3889.05	1.08	-20.0, 26.2	4.0	-31.8, 32.0
H_η	3835.38	1.06	-20.0, 14.6	4.0	-20.7, 21.8
H_θ	3797.90	1.05	-16.0, 16.0	3.9	-15.6, 16.7
H_ι	3770.63	1.04	-13.0, 13.0	3.9	-11.7, 11.6
He II 4686	4685.70	1.30	-11.9, 11.9	4.9	-15.0, 13.8
He I 4472	4471.60	1.24	-15.0, 15.0	4.6	-15.0, 15.0
He I 4026	4026.29	1.11	-24.2, 15.0	4.2	-15.0, 15.0
He I 4922	4921.93	1.36	-15.0, 15.0	5.1	-15.0, 15.0