Double Stars
The earliest known double stars:
- About 130 AD: Nu1 and Nu2 Sagittarii (an optical pair separated by 14') was
described as Double Star by Ptolemy (c. 85-165 AD) in Alexandria, Egypt.
- January, 1617: Mizar (Zeta Ursae Majoris)
discovered by Benedetto Castelli (1578-1643), a friend of Galileo.
See Tom Popper's and Jim Mosher's study on
Mizar through the
Galilean telescope and
Leos Ondra's review
article (also Ondra 2004).
1650: Mizar independently found double by Father Giovanni Baptista Riccioli
(1598-1671) in Bologna. This was the first recognized double star "discovery"
until the 1990s.
- January 30, 1617: Benedetto Castelli described a double star in Monoceros.
- February 4, 1617: Theta1 Orionis, the bright
stellar object in the Orion
Nebula (M42) observed as triple by
Galileo.
See Tom Popper's and Jim Mosher's study on
The Trapezium
through the Galilean telescope.
1656: Theta1 Orionis independently revealed as triple and described by
Christiaan Huygens (1629-95)
1673: Theta1 Orionis D found by
Abbe Jean Picard (1620-1682) to complete the "Trapezium."
1684: The fourth Trapezium star was independently recovered by Christiaan
Huygens.
Actually, the Trapezium is a cluster which includes many more stars, which
are all very young and have recently formed from matter of the
Orion Nebula.
- 1627: Benedetto Castelli discovered the 5th-mag companion to Beta Scorpii.
- 1664 or 1665: Gamma Arietis revealed as double by Robert Hooke (1635-1703)
in England
- 1685: Alpha Crucis recognized as double by Father Fontenay () at
the Cape of Good Hope, South Africa
- 1689: Alpha Centauri identified as double by Father Richaud ()
from Pondicherry, India
- 1718: Gamma Virginis
- 1719: Castor (Alpha Geminorum) identified by James Bradley (1693-1762)
in England
Double Star Stuff:
References:
Hartmut Frommert
[contact]