STARS WITH SPECTRAL PECULIARITIES
This directory contains some stars with unusual spectra (i.e., those
with spectra not on the OBAFGKM sequence, or with emission lines).
Not all stars with spectral peculiarities are expected to have unusual
polarization, so HPOL has not observed stars with all possible
The plots here may show somewhat different wavelength ranges than
the standards plots in order to show the spectral peculiarities better.
The plot header will give the star name or names,
maybe information about spectral type and the catalog in which it appears,
and date of observation.
Variations in extinction during a night can cause
the red and blue observation flux levels to not match.
AMMT Abt Meinel Morgan Tapscott An Atlas of Low
Dispersion Grating Stellar
C+J Cowley & Jaschek AJ 74, 375 1969
GGv69 Gray & Garrison ApJSup 69, 301
GGv70 Gray & Garrison ApJSup 70, 626
KM Keenan & McNeil An Atlas of
Spectra of the Cooler Stars
KM2 Keenan & McNeil ApJSup 71, 245
KY Keenan & Yorka BICDS 29,
ApJSupp 17, 371
MAT Morgan Abt Tapscott Revised MK
Spectral Atlas for Stars Earlier than
W Walborn ApJSupp 23,
Nariai, Norimoto An Atlas of Representative Stellar Spectra
P Cyg red; blue
The prototype P Cygni star; MAT has a spectrum. The term "P Cygni profile" refers to
an emission line with an absorption
line on its shortward wing. The HPOL spectrum resolution is not good enough
to see the absorptions well; they are
obvious on the MAT spectrm.
P Cyg red;
blue Same observation as above,
different vertical scale to show weaker emission lines better.
R Cor Bor red; blue; The prototype R CorBor star
Chi Oph red; blue B2Vne
Obvious emission at Halpha and Hbeta, higher hydrogen Balmer lines may be partly filled in;
also emission in the Paschen lines in the nearIR spectrum.
Alpha2 CVn; an Ap star.
Two nights plotted on the same graph,
with the second night plot shifted downward. This magnetic star has a period
of some five days; differences between the two spectra are not solely noise.
3 Wolf-Rayet stars:
HD191765: red; blue WN6
HD192641: red; blue WC7
EZ CMa: red; blue WN5
HR6497: red; blue A pair of
about A0V in a 3 day orbit with a G giant in a 1000+ day orbit. At the short wavelength end of the blue spectrum
the A stars dominate, at longer wavelengths features in the G star spectrum appear, and it dominates in the
HD25498: red; blue
About K0III + A3V. In this case the K star is a lot brighter relative to the A star than above. The short end
of the blue spectrum is noisy (star is faint and reddened), but the hydrogen lines are stronger than would
be expected for a K star; the K star dominates the red spectrum.
Though hard to see here because of the noisy blue spectrum, the higher hydrogen lines are easily
seen on a spectrum plate.
Spectroscopic binary data for this system is in Astron & Astrophys 473, 829 2007.
This star has several spectral types, from G0V to G0Ia, given in research papers in which spectral type was estimated
from photometry - which does not work for systems with comparable brightness stars of greatly different temperatures.
Nova Cas 1995
Spectra taken over several months showing the evolution of the spectrum of this slow nova.
The first HPOL observation was made about 1 week after the discovery announcement; the discovery
came about 3 weeks after the initial explosion.
See IAU Circular 6283 for discussion of
some of these spectral changes by Space Astronomy Lab staff members.
CI Aql = Nova Aql 2000 = Nova Aql 1917
This is a recurrent nova; a white dwarf with a K star companion in a .6 day orbit.
Observations were made 4 and 6 days after the outburst was discovered, which in turn must have
been several days after the outburst occurred.
The P Cygni absorption in the hydrogen Balmer lines is stronger two days later: