ZETA (ζ) BOÖTIS
MULTIPLE STAR

Right Ascension:
14h 41m 08s

Best Seen:
4/15 - 8/15

Declination:
13º 43' 42" Combined
Magnitude:
3.78

Computer File:
zetaboo

Constellation:
Bootes

Apparent
Separation: 1"

Actual

Compared to

Distance

180 l.y.

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Separation

~ 3.1 billion miles

~ 33 Earth/Sun

Orbital Period

~ 120 years

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Actual Brightness

--

37 / 36 (Sun)

Magnitude

4.53 / 4.58

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Mass

Surface Gravity

--

--

Surface Composition (by mass)

74% hydrogen 24% helium 2% everything else

same (Sun)

Spectral Type

A3 IV n / A2 V

G2 V (Sun)

Density (gram/cubic cm)

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WHAT TO LOOK FOR THROUGH THE TELESCOPE:

  1. Recommended eyepiece: 24mm or 40 mm.

  2. When people look through the telescope they should see two stars next to each other. One star should be slightly brighter than the other.

ZETA BOÖTIS INFORMATION:

  1. The orbits of these stars could set a record: the orbits are very elongated.

a. At their farthest, the stars are about 60 AU’s apart; at their closest, they’re about 1.5 AU’s apart, about as close as Mars to the Sun.

b. At close passage, the individual stars cannot be resolved – that happened last in 1897, and will happen again in 2021.

c. At their farthest separation, they can be resolved – the best view will be in 2082.

  1. This large eccentricity could be the result of a violent encounter with another star, but it’s impossible to know.

Item
Updated Notes

Coordinates 11-08-2002
updated with SIMBAD

Combined Magnitude
11-08-2002
previously: 4.60 – now matches Scott’s The Flamsteed Collection

Apparent Separation 11-08-2002
previously: 7" – NO idea where that came from: coordinates are identical in RA, DEC is only different 1"

Distance
11-08-2002
previously: 88 ly – BUT Flamsteed and SIMBAD say otherwise

Separation
11-08-2002
previously: 50 Earth/Sun – new info from http://www.astro.uiuc.edu/~kaler/sow/zetaboo.html

Orbital Period
11-22-2002
http://www.astro.uiuc.edu/~kaler/sow/zetaboo.html

Actual Brightness
11-08-2002
with Scott’s Flamsteed

Magnitude
11-08-2002
with Flamsteed

Mass

Surface Gravity

Surface Composition 01-06-2003
OK for all stars

Spectral Type
11-08-2002
with Flamsteed

Density

Other Information
11-08-2002
with http://www.astro.uiuc.edu/~kaler/sow/zetaboo.html