Historical clue formulations

• Brightest point in Canis Major, familiarly — 2023-06-09
• Sirius ... or Lassie, for example? — 2020-11-16
• Sirius — 2015-09-24
• Bright spot? — 2015-04-12
• Sirius — 2012-08-22
• Bright spot in the night sky — 2009-04-12
• Part of Canis Major — 2000-06-27