From jop at astro.columbia.edu Fri Apr 1 01:02:07 2022 From: jop at astro.columbia.edu (Joe Patterson) Date: Fri, 1 Apr 2022 01:02:07 -0400 Subject: (cba:news) April sky calendar Message-ID: Hi CBAers, OK, this is not cba-news at all. Still... In the late 1970s, I wrote sky calendars for Univ.of Texas... which eventually mutated into the radio program which some of you probably know. Then for a few years in the 1990s, I wrote something similar for Columbia/NYC. Now I'm up to it again, this time for Pioneer Works, an art-and-science institute in Brooklyn. I think this one will be a keeper. The last few months have reminded me how much I really like to write... and the main audience for Pioneer Works (people who like art, I think) is a new challenge for me. In theory, I'll have much more time to write, starting in June. Both science and "popular". https://pioneerworks.org/broadcast/big-apple-sky-calendar-april-2022 Suggestions very welcome! joe ____________________________________________________________ Center for Backyard Astrophysics (CBA) mailing lists https://cbastro.org/communications/mailing-lists/ From jop at astro.columbia.edu Fri Apr 8 06:53:17 2022 From: jop at astro.columbia.edu (Joe Patterson) Date: Fri, 8 Apr 2022 06:53:17 -0400 Subject: (cba:news) V1674 Her... once more with feeling! Message-ID: <0053ffe0-96b0-e6f9-02c6-061194684aeb@astro.columbia.edu> Hi CBAers, A recent ATel suggests that V1674 Her has "returned to quiescence". I'm not sure exactly what the authors meant by this... maybe simply that the spectrum now resembles a CV rather than a nova. But all of our data shows that it's still 3 magnitudes above quiescence, and exhibiting the same periodic phenomena which characterized the eruptive state (3.5 hours and 8 minutes). In particular, the pulsation period continues to speed up, as it did throughout 2021. There's a lot of physics in that change of pulse period. And it's all NEW physics. Never before have we had a star with known pulse period *before* eruption, known pulse period ~10 days after eruption, and then continuously known dP/dt for the next 300 days (and counting). Maybe when we have 10 TESSs and ZTFs, such things will be routine. But it's all terra incognita now, and I earnestly hope you guys keep the time series coming! It gets 4 minutes better every day... but even now, Hercules is well up in the morning sky. We are just getting started on this amazing star... and I bet others are, too. In the history of novae, I think it will take a high place in the pantheon, alongside DQ Her, T Pyx, and V1500 Cyg. joe ____________________________________________________________ Center for Backyard Astrophysics (CBA) mailing lists https://cbastro.org/communications/mailing-lists/