|1950||19Delta LIB||19Delta LIB|
|20Sigma LIB||20Sigma LIB||20Sigma LIB||20Sigma LIB|
|2000||19Delta LIB||19Delta LIB||19Delta LIB|
|20Sigma LIB||20Sigma LIB|
In some cases you have a choice. Remember that a brighter star has a smaller magnitude number, if that is your choice.
Name: 19Delta LIB
Birthday from Jack’s initial research: Nov 9
Magnitude: 4.8, variable
Spectrum/Star type: blue-white
Distance in Light Years: 305
Diameter compared to Sun: 3 and 4
Luminosity compared to Sun: 45 and 3
Date best observed: Jun 21
Additional information: This is an Algol eclipsing variable star with a 2.3 day period. 2 oval shaped stars are orbitng each other. A smaller but brighter star is eclipsed by a larger, dimmer star. The magnitude dims to 5.9, then later returns to 4.8.
Name: 20Sigma LIB Brachium
Birthday from Jack’s initial research: Nov 10
Magnitude: 3.3, variable
Spectrum/Star type: Red giant
Distance in Light Years: 290
Diameter compared to Sun: 110
Luminosity compared to Sun: 1900
Date best observed: Jun 22
Additional information: Latin for “Arm”, referring to the Scorpion. This star was once known as gamma sco. A semi-regular variable, it changes from magnitude 3.2 to 3.4 over 20 days. It will become like the famous star Mira some day, dimming to invisibility for long periods. In Upton’s Star Atlas of 1896, Sigma, Tau, and Upsilon LIB were still shown to be in the Scorpion!