EPSILON (ε) LYRAE
OPTICAL DOUBLE STAR
Right Ascension:
18h 44m 21.6s
Best Seen:
6/15 -12/1
Declination:
38º 32' 00"
Combined
Magnitude:
4.67 / 4.59
Computer File:
Epslyr
Constellation:
Lyra
Apparent
Separation:
211"
EPSILON I (Northern Pair)
EPSILON II (Southern Pair)
Actual
Compared to Sun
Actual
Compared to Sun
Distance
162 l.y.
160 l.y
Actual Brightness
--
19 / 6.5
--
14 / 12
Magnitude
5.06 / 6.19
5.30 / 5.51
Mass
--
--
Surface Gravity
--
--
Surface Composition (by mass)
see below
same
see below
same
Spectral Type
A4 V / F1 V G2 V
A8Vn / F0Vn 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 they should see two stars near each other. One star should be slightly brighter than the other. Each star should look slightly oval shaped.
-
With good atmosphere conditions and/or with good eyes, it can be seen that each star is really two stars.
EPSILON LYRAE INFORMATION:
-
This is the famous “Double Double” star. (With our understanding of distances and multiple stars, a more accurate name would be the “Double Multiple.”)
-
The surface composition of these stars, by mass, is 70% hydrogen, 28% helium, and 2% everything else. (The composition of the stars’ cores depend on what stage of life they’re in.)
Item
Updated
Notes
Coordinates
12-02-2002
split difference between “two”
Combined Magnitude
12-02-2002
with Scott’s The Flamsteed Collection
Apparent Separation
12-02-2002
from coordinates given in Flamsteed:
e1: 18 44 20.2 39 40 15
e2: 18 44 23.0 39 36 46
Distance
12-06-2002
with Flamsteed
Actual Brightness
12-06-2002
with Flamsteed
Magnitude
12-06-2002
with Flamsteed
Mass
Surface Gravity
Surface Composition
01-06-2003
OK for all stars... it wouldn’t fit in chart, so had to put it in “other information”
Spectral Type
12-06-2002
with Flamsteed and SIMBAD