From jop at astro.columbia.edu Sun Oct 17 04:52:33 2021 From: jop at astro.columbia.edu (Joe Patterson) Date: Sun, 17 Oct 2021 04:52:33 -0400 Subject: (cba:news) V1674 Herculis: sayonara? Message-ID: <8fc55f93-087f-f5ea-58b8-2f432f20e4f9@astro.columbia.edu> Hi CBAers, A hearty thanks to all of you who have been battling airmass to sustain the campaign on Nova Her 2021. Most professional astronomers switched allegiance to RS Oph when that venerable star erupted a few weeks later... but the Nova Her campaign has been thrilling to me - the most exciting nova since V1500 Cyg. With its pronounced orbital and spin signals, this star has taught me lessons about how the nova outburst affects the mass-transfer process. But the time baseline of data is now 125 days, and the star is getting LOW in the west. Except to check for surprises, it's probably time to switch allegiance. Here's a good shopping list for Oct-Nov 2021: V1500 Cyg, CC Scl, V598 Peg, QR And, ES Cet, V902 Mon, T Aur. And V Per. As usual, it pays to concentrate on a particular star, as long as airmass and telescope aperture permit. The long-run-every-night observing style tends to bring rewards unattainable in other ways. (And speaking of that, special thanks to David Cejudo and Richard Sabo for their fidelity to V1500 Cyg and V1974 Cyg this year.) Also BT Mon, the deep-eclipsing nova of 1939. This one is a special case, since P_orb is so close to 8.00 hours that your nights can be highly redundant. Some communication of early-season eclipse times would be good. In general, the detailed shape of the ORBITAL light curve of old novae is a subject I plan to focus on this year. I've certainly left off a few that could be interesting - and there's likely some interesting physics in that subject. joe p ____________________________________________________________ Center for Backyard Astrophysics (CBA) mailing lists https://cbastro.org/communications/mailing-lists/ From jop at astro.columbia.edu Sun Oct 24 09:52:09 2021 From: jop at astro.columbia.edu (Joe Patterson) Date: Sun, 24 Oct 2021 09:52:09 -0400 Subject: (cba:news) V1674 Her, one more time... Message-ID: Hi CBAers, It's getting late in the year for Hercules, but not hopelessly so. I really would appreciate another 1-2 weeks of coverage! The 8-minute "spin" period is getting stronger and stronger (in magnitude units) as the star fades (now mag 16.6). This is the first time that a DQ Her star (IP) has ever given us an opportunity to see how the nova eruption affects the (alleged) magnetically channeled accretion. We might have to wait another century for the next opportunity. I'm also scrounging for data during the first 15-20 days of outburst. We have excellent data on JD 9382 and 9394, and a completely continuous record since JD 9400. But there's probably some other data out there in the first ~15 days since eruption on JD 9378. Do you have any, or know of any, or can retrieve any? We have LOTS of data on this fascinating star, and it has been an immense pleasure to study it. But the periodic behavior in the first ~2 weeks is so startling that... well, I need some help! joe ____________________________________________________________ Center for Backyard Astrophysics (CBA) mailing lists https://cbastro.org/communications/mailing-lists/