EW Lacertae — Star in Lacerta
Observe
1Physical Properties
Magnitude
5.43
Range
5.22 - 5.48
Period
8.7 hours
Variable Type
Gamma Cassiopeiae (Eruptive Be Star)
Spectral Type
B4IIIep
Star Color
Blue-white
(B-V -0.09)
2Position & Identifiers
RA
22h 57m 04.5s
Dec
+48° 41' 03.0"
Constellation
Lacerta
(Lac)
HR
8731
HIP
113327
HD
217050
Variable ID
EW Lac
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3How easy to spot?
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| Equipment | Bortle 3 | Bortle 4 | Bortle 5 |
|---|---|---|---|
| Naked eye Naked eye | Medium | Hard+ | Hard |
| 50 mm finder 50mm finder | Easy | Easy | Easy |
| 150 mm telescope 150mm scope | Easy | Easy | Easy |
Easy
Medium
Hard
Very hard
Impossible
Bortle 3 = rural · 4 = outer suburbs · 5 = suburbs
4Visibility
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Best season
Jul – Sep
(peak: Aug)
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5
Size Comparison
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6
Compare Stars
7
Spectral Classification
8
Hertzsprung-Russell Diagram
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9
Stellar Lifecycle
10
Blackbody Spectrum
11
Stellar Absorption Spectrum
Simulated absorption spectrum based on spectral type. Hover over lines to identify elements.
12
Stellar Fusion
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13Stellar Notes
Gamma Cas 5.22 - 5.48V, 5.0 - 5.3p; later observations 5.15 - 5.21V. Amp. variable. Periods at different times have | varied from 0.7364 in 1951 to between 0.800 and 0.700d; more recent periods were a choice in 1980 between 0.725 and | 0.418d; 0.711 in 1981 and then 0.722d. Also indications of long-term changes. Spectrum variable 2.4 - 10.8y. Spectrum | also indicates atmospheric quasi-periodic pulsations of about 1d. Strong spectrum and color changes in 1978.
Shell star.
Variation in envelope, about 19d. Non-expanding over 50y. Rotating metal shell.
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Visibility scores assume a 150 mm Newton at Bortle 4.
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