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Fomalhaut
FOMALHAUT (ALPHA (α) PISCIS AUSTRINI)
BLUE STAR
Right Ascension:
22h 57m 39s
Best Seen:
11/1-12/1
Declination:
-29º 37' 20"
Magnitude:
1.17
Computer File:
fomalhau
Constellation:
Piscis Austrinus
Actual
Compared to Sun
Distance
25 l.y.
--
Actual Brightness
--
16
Surface Temperature
~18,000 ºF
~1.8
Diameter
~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:
-
Recommended eyepiece: 24mm or 40 mm.
-
When people look through the telescope a bright bluish point of light should be seen.
FOMALHAUT INFORMATION:
-
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).
-
Fomalhaut is surrounded by a circumstellar dust disk, shaped like a doughnut.
a. 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.
b. The “inside” of the doughnut might have been carved out by a planet.
Item
Updated
Notes
Coordinates
07-17-2002
SIMBAD
Distance
07-17-2002
SIMBAD, with Hipparcos
Actual Brightness
07-17-2002
with Scott’s The Flamsteed Collection
Surface Temperature
07-17-2002
A type star approx 10,000K
Diameter
07-17-2002
with A type star approx 10,000K
Mass
07-17-2002
with mass-lum rel: L = M3.5
Surface Composition
01-06-2003
OK for all stars
Spectral Type
–
Other Information
07-17-2002
07-17-2002
07-22-2002
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 7/30/13 Changed to 74% / 24% / 2%