Possible Clues:

• Comet Hale-__
• 1995 comet spotter Thomas
• Hale-___ comet
• Hale-___ (comet seen in 1997)
• Comet Hale-___
• He independently discovered the same comet as Hale
• Astronomer Thomas for whom a comet is named
• Hale- — (comet)
• 1995 comet observer
• Comet Hale- --