J/A+AS/147/5 AS 78 & MWC 657 spectroscopy (Miroshnichenko+, 2000)
Spectroscopy and photometry of the emission-line B-type stars AS 78 and MWC 657
Miroshnichenko A.S., Chentsov E.L., Klochkova V.G., Kuratov K.S.,
Sheikina T.A., Mukanov D.B., Bjorkman K.S., Gray R.O., Rudy R.J.,
Lynch D.K., Mazuk S., Puetter R., Garcia-Lario P., Perea J.V., Bergner Yu.K.
<Astron. Astrophys. Suppl. Ser. 147, 5 (2000)>
=2000A&AS..147....5M 2000A&AS..147....5M
ADC_Keywords: Stars, B-type ; Stars, emission ; Equivalent widths ;
Radial velocities
Keywords: techniques: photometric - techniques: spectroscopic -
stars: emission-line - stars: circumstellar matter -
stars: individual (AS 78, MWC 657)
Abstract:
We present the results of low- and high-resolution spectroscopic and
multicolour photometric observations of two early-type emission-line
stars, AS 78 and MWC 657. They were identified by Dong & Hu
(1991ChA&A..15..275D 1991ChA&A..15..275D) with the IRAS sources 03549+5602 and 22407+6008,
respectively, among many other sources displaying a very strong
infrared excess, V-[25]≥8mag. AS 78 is recognized as a photometric
variable for the first time. A large near-IR excess radiation is
detected in AS 78 and confirmed by new, higher-quality, data for
MWC 657. Significant variations in the Balmer line profiles are
detected for both objects. Modelling of the Balmer line profiles of AS
78 obtained in 1994 yields the following parameters of the star and
its wind: Teff∼17000K, logLbol/L☉∼4.0,
dM/dt∼10-6M☉/yr. The photometric and new spectroscopic data
indicate that the star's Teff increases with time, while the stellar
wind changes its structure. Distances towards both objects are
estimated on the basis of their radial velocities and the galactic
rotation curve. Consideration of different options about the nature
and evolutionary state of both objects leads us to suggest that they
are binary systems containing a B-type intermediate-luminosity star
and a gaseous disk around the less luminous component.
Objects:
-----------------------------------------
RA (2000) DE Designation(s)
-----------------------------------------
03 58 59.7 +56 11 13 AS 78
22 42 42.2 +60 24 01 MWC 657
-----------------------------------------
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table9.dat 93 107 Lines identified in the optical spectra of
AS 78 and MWC 657
table9.tex 121 206 LaTeX version of table 9
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See also:
J/A+AS/104/315 : Member of Herbig Ae/Be stellar group (The+ 1994)
Byte-by-byte Description of file: table9.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Ident Line identifications (1)
11- 18 F8.2 0.1nm LambdaLab Laboratory wavelength
19- 23 F5.2 --- Ipeak1 ? MWC 657 peak intensity for the line
normalized to the continuum (1994 OHP)
24 A1 --- u_Ipeak1 Uncertainty flag on Ipeak1 (2)
25- 29 I5 km/s HRV1 ? MWC 657 heliocentric radial velocity
(1994 OHP)
30 A1 --- u_HRV1 Uncertainty flag on HRV1 (2)
31- 35 F5.2 0.1nm EW1 ? MWC 657 equivalent width (1994 OHP)
36- 43 A8 --- Note1 Note on lines (3)
44- 48 F5.2 --- Ipeak2 ? MWC 657 Peak intensity for the line
normalized to the continuum (1999 SAO)
49 A1 --- u_Ipeak2 Uncertainty flag on Ipeak2 (2)
50- 54 I5 km/s HRV2 ? MWC 657 heliocentric radial velocity
(1999 SAO)
55 A1 --- u_HRV2 Uncertainty flag on HRV2 (2)
56- 60 F5.2 0.1nm EW2 ? MWC 657 equivalent width (1999 SAO)
61- 68 A8 --- Note2 Note on lines (3)
69- 73 F5.2 --- Ipeak3 ? AS 78 peak intensity for the line
normalized to the continuum (1999 SAO)
74 A1 --- u_Ipeak3 Uncertainty flag on Ipeak3 (2)
75- 79 I5 km/s HRV3 ? AS 78 heliocentric radial velocity
(1999 SAO)
80 A1 --- u_HRV3 Uncertainty flag on HRV3 (2)
81- 85 F5.2 0.1nm EW3 ? AS 78 equivalent width (1999 SAO)
86- 93 A8 --- Note3 Note on lines (3)
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Note (1): Uncertain identifications are marked with colons, ?: indicates
uncertain line presence
Note (2): Measurements of a low accuracy are marked with colons
Note (3): Notes:
"P Cyg" : P Cyg-type profiles
"P Cyg:" : weak absorption component with an intensity of larger than
0.95 of the continuum
"+f" refers to the following line
"+p" refers to the preceding line
"compl" : complicated profile
"blend" : blend with another line
For the Na I 5889 and 5895 lines in the OHP spectrum of MWC 657,
RV of two additional absorption components are listed.
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Acknowledgements: Anatoly Miroshnichenko
(End) Patricia Bauer [CDS] 17-Aug-2000