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Alpha (α) Scorpii
Antares
Red Supergiant Star
| Right Ascension | 16h 29m 24s | Best Seen | 7/15 - 9/15 |
| Declination | -26° 25' 55" | Magnitude | 1.06 |
| Constellation | Scorpius | ||
| Actual | Compared to Sun | |
| Distance | ~604 ly | -- |
| Actual Brightness | -- | 10,100 |
| Surface Temperature | ~5,900 °F | ~0.6 |
| Diameter | ~500 million miles | 575 |
| Mass | -- | 15 - 18 |
| Surface Gravity | -- | -- |
| Surface Composition (by mass) | 74% hydrogen 24% helium 2% everything else |
same |
| Spectral Type | M1 Ib | 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 a bright reddish-orange point of light should be seen.
Antares Information:
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Antares is the 11th brightest star in the Northern Hemisphere’s night sky (16th brightest if including the Southern Hemisphere’s nighttime stars.
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This is probably the second largest of the bright stars in the sky. (Betelgeuse is larger).
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Antares has a companion:
| Magnitude | 6.5 |
| Luminosity | 50 times that of the sun |
| Spectral Type | B2.5 |
| Separation | 45 billion miles (500 times Earth-Sun distance) |
| Period | 853 years |
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References
| Item | Updated | Notes |
| Coordinates | 2003-01-06 | tweaked a bit |
| Magnitude | 2005-05-19 | previously: 0.92 – BUT this matches with Scott’s The Flamsteed Collection and SIMBAD Crosschecked. studies vary from +0.92 to 1.1 so number OK. |
| Distance | 2005-05-19 | previously: 520 – BUT this matches with Flamsteed and SIMBAD OK. Croschecked with paper Krudrizki&Reimers, 1978, Astron. And Astrophys. Vol 70 p.227 Their numbers: 180 pc, SIMBAD -185 pc |
| Actual Brightness | 2003-01-06 | previously 9,000 – BUT this matches with Flamsteed |
| Surface Temperature | 2005-05-19 | supported by http://www.astro.uiuc.edu/projects/sow/antares.html Croschecked with paper Krudrizki&Reimers, 1978, Astron. And Astrophys. Vol 70 p. 227. They have 3,550k which comes out to 5,900F |
| Diameter | 2003-01-06 | previously 600 million miles / 700 times sun – BUT site says over 4 AU’s http://www.astro.uiuc.edu/projects/sow/antares.html Changed from 740 million miles and 860 Suns. No book or net source agrees with this high number. Croschecked with paper Krudrizki &Reimers, 1978, Astron. And Astrophys. Vol 70 p. 227. They have 575 times the Radius of the Sun. |
| Mass | 2005-05-19 | Croschecked with paper Krudrizki&Reimers, 1978, Astron. And Astrophys. Vol 70 p. 227. They have 18 solar masses |
| Surface Gravity | -- | |
| Surface Composition | 2003-01-06 | OK for all stars |
| Spectral Type | 2003-01-06 | OK with SIMBAD and Flamsteed |
| Density | 2003-01-06 | previously: <10-6 – BUT can find no support |
| Other Information | 2003-01-06 | can’t confirm luminosity, separation, or period, but looks OK brightness rank from Hipparcos site |