AAVSO webinar, with Dr. David Whelan (Austin College)
3:23:46
AAVSO Spectroscopy Workshop, Day1 (2020)
1:25:24
Understand photometric transforms & filters with Brian Kloppenborg
5:15
Size comparison 2023-2025 part 10
2:11:25
Backyard astronomical spectroscopy with Bob Buchheim & Scott Donnell
1:32:03
How to observe in the city
2:40:55
How To: Introductory Photometry
26:26
Les forces ukrainiennes débordées face aux soldats russes
22:02