Beta Lyrae stars
Beta Lyrae is an eclipsing interacting binary star. Beta Lyrae is the prototype of this class
of eclipsing binaries. Every 12.938 days it drops from 3.3 to 4.3
magnitude (the period evolve). The secondary minimum is about
magnitude 3.8.
The primary star of this close binary is classified as a giant of type B7Ve and probably has about twice the mass of the Sun. The secondary star seems to be largely invisible even though it appears to be far more massive with about 12 times the Sun's mass. The secondary is probably concealed at least partially by a thick, opaque torus of matter orbiting and spiraling into it.
Helium lines are very variables and this variations are related to phase. Ha variability can presumable be explained by the fact that the secondary component (B-star with thick disc) is being covered by the B6 star and that only the continuum intensity is varying due to the eclipsing process.
A list of bright Beta Lyrae type stars (m<6):
HD Star R.A. Dec. Mag. range Period (J) Spec.
4502 Zeta
And 00 47 21 +24
16 06 3.92-4.14 17.7695
K1II-III
39220 31
Cam 05 54 58 +59
53 19 5.12-5.29 2.9332
A0IV-V
42933 Delta
Pic 06 10 18 -54
58 08 4.65-4.90 1.6725
B3III+O9V
57060 29
CMa 07 18 40 -24
33 32 4.84-5.33 4.3934
O7Ia:fp+OB
61429 PU
Pup 07 38 18 -25
21 53 4.69-4.75 2.5789
B9
65818 V Pup 07
58 14 -49 14 42 4.35-4.92
1.4545 B1Vp+B3:
124195 V716 Cen 14
13 40 -54 37 32 5.96-6.52
1.4901 B5V
135876 GG Lup 15
18 56 -40 47 16 5.49-6.00
2.1642 B7V
181615 Upsilon Sgr 16 21 43 -15
57 18 4.53-4.61 137.939
B8pI:+O9V
151890 Mu 1 Sco
16 51 52 -38
02 50 2.94-3.22 1.4463
B1.5V+B6.5V
174638 Beta
Lyr 18 50 05 +33
21 46 3.25-4.36 12.8380
B8II-IIIep
185507 Sigma
Aql 19 39 12 +05
23 52 5.14-5.34 1.9502
B3V+B3V
199603 DV Aqr 20
58 42 -14 28 58 5.89-6.25
1.5755 F0IV
216200 14 Lac 22
50 22 +41 57 13 5.91-5.98
10.0750 B3IV:eaV
Beta Lyrae observations
Reciprocal dispersion of 4 A/pixel
Click on the images to enlarge.
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