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Albireo
Beta (β) Cygni
Contrast Optical Double Star
| Right Ascension | 19h 30m 43s | Best Seen | 6/15 - 11/15 |
| Declination | 27° 57' 35" | Magnitude (combined) | 3.05 |
| Apparent Separation | 34.4" | Constellation | Cygnus |
| 4,620 au |
Actual |
Compared to Sun |
|
| Distance | 385 / 376 ly | -- |
| Actual Brightness | -- | 497 / 94 |
| Apparant Magnitude | 3.08 / 5.12 | |
| Absolute Magnitude | -2.2 / -0.2 | |
| Size | -- | ~20 / ~3 Solar Radius |
| Mass | -- | ~4 / ~6 Solar Mass |
| Surface Gravity | -- | -- |
| Surface Composition (by mass) | 74% hydrogen 24% helium 2% everything else |
same |
| Spectral Type | K3 II / B8 Ve | G2 V |
| Density (gram/cubic cm) | -- | -- |
What To Look For Through The Telescope
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Recommended eyepiece: 24mm or 40 mm.
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When people look through the telescope they should see two stars next to each other. The brighter star should appear yellow and the dimmer star blue.
Albireo Information:
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The 5th brightest star in Cygnus, Albireo is one of the best known contrast optical double stars.
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The yellow star is actually a multiple star system: the star and an unseen companion orbit each other.
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In Arabic, “Minqar al-Dajajah,” meaning “the hen’s beak” - otherwise known as the “beak star”.
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Light we’re seeing left in 1586 AD:
- 1580 - Sir Francis Drake completes his circumnavigation of the globe…his is the 2nd journey to do that and the first under the same commander.
- 1582 – the Gregorian calendar is implemented
- 1582 – Shakespeare marries Anne Hathaway
- 1580s – Chocolate is introduced commercially to Europe
- 1587 – Mary Queen of Scots is beheaded
- 1587 – English settlers arrive at Roanoake Island in North Carolina and re-establish the deserted colony
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If they are orbiting each other (we don’t know for certain), their orbital period is at least 75,000 years
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Beta1 Cyg or Albireo A (the golden amber star):
Color Orange, K3 II, bright giant Luminosity 889 Suns; 1460 Suns total Diameter 66 Suns Absolute Magnitude -2.55 visual; -3.16 total a. In 1976, it was discovered that this is a binary system in itself, separated by 40 AU, and orbiting each other every 100-200 years. Our telescope can’t distinguish between them.
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The brighter star is a helium-fusing giant, class K3 (orange)
Temperature 7440⁰ F Luminosity 950 Suns Diameter 50 Suns Mass 5 Suns -
The other is a hydrogen-fusing main sequence, class B9 (blue)
Temperature 19,340⁰ F Luminosity 100 Suns Mass 3.2 Suns
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Beta2 Cyg or Albireo B (the blue-white star):
Color B8 Ve, main sequence Temperature 20,100⁰ F Luminosity 117 Suns visual; 229 Suns total Diameter 3.88 Suns Absolute Magnitude -0.35 visual; -1.15 total a. Very fast spinning star (150 miles per second), rotation period of about 14 hours, this causes a gas disk around it
b. From Albireo B, Albireo A would appear as brilliant orange and blue points about ½ degree apart. The orange star would shine with light equal to about 35 full moons, and the blue/white companion about ½ half that.
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References
| Item | Updated | Notes |
| Coordinates | 2002-07-24 | SIMBAD, The Flamsteed Collection |
| Combined Magnitude | 2002-07-24 | with Scott’s The Flamsteed Collection |
| Apparent Separation | 2002-07-24 | http://www.astronomical.org/constellations/cyg.html |
| Distance | -- | |
| Actual Brightness | -- | |
| Magnitude | 2002-07-24 | with Scott’s Starlist 2000 |
| Mass | -- | |
| Surface Gravity | -- | |
| Surface Composition | 2003-01-06 | OK for all stars |
| Spectral Type | 2002-07-24 | SIMBAD |
| Density | -- | |
| Other Information | ||
| Size, Mass | 2005-05-04 | 1. previous: “About 60 of our solar systems could be laid edge to edge between these two stars.” – BUT much more, so took out. 2. Add info about binary found at http://www.daviddarling.info/encyclopedia/A/Albireo.html Other data found using app.mag, dist. and spectral class on a graph of the HR diagram |