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Fomalhaut

Alpha (α) Piscis Austrini
Blue Star
Right Ascension 22h 57m 39s Best Seen 11/1 - 12/1
Declination =29° 37' 20" Magnitude 1.17
Constellation Piscis Austrinus

Actual		 Compared
to Sun
Distance ~25 ly --
Actual Brightness -- 16
Surface Temperature ~18,000 ºF ~1.8
Diameter (average) ~1.12 million miles ~1.34
Mass -- 2.2
Surface Gravity -- --
Surface Composition (by mass) 74% hydrogen
24% helium
2% everything else		 same
Spectral Type A3 V G2 V
Density (gram/cubic cm) -- --

What To Look For Through The Telescope

  1. Recommended eyepiece: 24mm or 40 mm.

  2. When people look through the telescope a bright bluish point of light should be seen.

Fomalhaut Information:

  1. Fomalhaut is the 13th brightest star in the Northern Hemisphere’s night sky (18th brightest in the night sky when including Southern Hemisphere’s bright stars).

  2. Fomalhaut is surrounded by a circumstellar dust disk, shaped like a doughnut.

    1. The “outside” of the doughnut extends about 140 A.U. from Fomalhaut.
      By comparison, the planet Pluto is about 40 A.U. from our Sun.

    2. The “inside” of the doughnut might have been carved out by a planet.
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References
Item Updated Notes
Coordinates 2002-07-17 SIMBAD
Distance 2002-07-17 SIMBAD, with Hipparcos
Actual Brightness 2002-07-17 with Scott’s The Flamsteed Collection
Surface Temperature 2002-07-17 A type star approx 10,000K
Diameter 2002-07-17 with A type star approx 10,000K
Mass 2002-07-17 with mass-lum rel: L = M3.5
Surface Composition 2003-01-06 OK for all stars
Spectral Type –- --
Other Information 2002-07-22 1. previously:
“2a. It also apparently has a red dwarf companion.
Spectral Type: K5
Luminosity: 10% of the sun’s luminosity
Separation: ~1 light year
2b. This may not be a gravitationally bound pair.”
BUT I can’t find any evidence of this companion.
2. added info about circumstellar disk
3. with Hipparcos, brightness “rank”
Composition 2013-07-30 Changed to 74% / 24% / 2%