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Alpha (α) Canum Venaticorum
Cor Caroli
Optical Double Star
| Right Ascension | 12h 56m 01s | Best Seen | 4/1 - 9/1 |
| Declination | 38° 19' 00" | Combined Magnitude | 2.80 |
| Apparent Separation | 23.4" | Constellation | Canes Venatici |
Actual |
Compared to Sun |
|
| Distance | 110 / 82 ly | -- |
| Actual Brightness | -- | 63 / 2.8 |
| Magnitude | 2.89 / 5.61 | -- |
| Mass | -- | -- |
| Surface Gravity | -- | -- |
| Surface Composition (by mass) | 74% hydrogen 24% helium 2% everything else |
same |
| Spectral Type | A0p / F0 V | 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 near each other. One star should be slightly brighter than the other.
Alpha Canum Venaticorum Information:
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Unlike many constellations, Canes Venatici, the Hunting Dogs, is a modern constellation, invented by the 17th century astronomer Hevelius to fill in gaps left by the ancients.
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The primary star is called Cor Caroli, “The Heart of Charles.”
a. One story is that Edmund Halley gave this name in honor of England’s King Charles II.
b. More likely, the star’s original name was Cor Caroli Regis Martyris, honoring the executed King Charles I.
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Cor Caroli marks the dog Chara, while the other star in the constellation marks the dog Asterion.
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The brighter star, Cor Caroli, is actually called Alpha 2 because of its position in the sky relative to Alpha 1.
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Cor Caroli is a “magnetic” star, possessing one of the strongest magnetic fields of otherwise normal main sequence star. Whereas our sun’s overall magnetic field is a few times more than Earth’s Cor Caroli’s magnetic field is about 1500 times stronger.
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References
| Item | Updated | Notes |
| Coordinates | 2002-11-18 | with Scott’s Flamsteed Collection, but gave average value between the two |
| Combined Magnitude | 2002-11-18-2002 | OK with Scott’s Flamsteed |
| Apparent Separation | 2002-11-18 | from coordinates |
| Distance | 2002-11-18 | from Flamsteed and matches SIMBAD |
| Actual Brightness | 2002-11-18 | from Flamsteed |
| Magnitude | 2002-11-18 | OK with Flamsteed |
| Mass | -- | |
| Surface Gravity | -- | |
| Surface Composition | 2003-01-06 | OK for all stars |
| Spectral Type | 2002-11-18 | OK with Flamsteed, close match to SIMBAD |
| Density | -- | |
| Other Information | 2002-11-18 | http://www.astro.uiuc.edu/~kaler/sow/corcaroli.html and http://www.dibonsmith.com/cvn_con.htm and Item 2b, Burnham’s and http://www.space.com/spacewatch/hunting_dog_020517.html |