开云体育

Hi all, Statistical question: given that this (non-sungrazing) comet seems to not be new (barycentric orbital period in the 30~80 thousand years at epoch 1900), i.e. its disintegration could supposingly have happened at any other approach before or after the current one, is this seeming disintegration at this specific approach a statistically unexpectable event (i.e. expectable lifetime / number of known similarly-long-period comets >> orbital period), or is it statistically not unlikely (i.e. expectable lifetime / number... << orbital period) -- and even more, unlikely or not to happen within "modern astronomy" (i.e. expectable lifetime / number... >> or << centuries)? Thank you in advance for your help. Adrien

Hi All. Just now was released CBET 5538 and SWAN25F = C/2025 F2 (SWAN)! My congratulations to Michael and Robert! Great job guys! I am also grateful to each and everyone who took part in this case - I proud that I can be a part of so good and so powerful astro-community. Also many thanks to Daniel Green and to CBAT and MPC staff. Vladimir.

Hi Michael and Vladimir, I actually have Michael at 11 SWAN comets (or 12 if you count 58P which Michael spotted in SWAN in April 2020) C/2004 H6, C/2004 V13, P/2005 P3, C/2005 T4, C/2006 M4, C/2015 C2, C/2015 F3, C/2015 P3 , C/2020 F8, C/2021 D1 and C/2025 F2. If my records are correct, I have Vladimir with 7 SWAN comets (some shared with Michael and/or me): P/2005 P3, C/2011 Q4, C/2012 E2, C/2015 C2, C/2015 F3, C/2023 A2, and C/2025 F2 My count is at 9 (many of which also shared with Michael and/or Vladimir), though as Michael pointed out one of these (C/2012 V4) turned out to be the recovery of D/1827 M1 = 273P Pons-Gambart, and another P/2018 HT3 was linked to an asteroid. --Rob From: [email protected] <[email protected]> On Behalf Of Michael Mattiazzo via groups.io Sent: Friday, April 11, 2025 3:57 PM To: [email protected] Subject: EXTERNAL: Re: [comets-ml] C/2025 F2 (SWAN) + coordinate conversion check Thanks Vladimir. I’m sure Rob has also found quite a few over the years, including some non SWAN named ones such as 273P Pons-Gambart and P/2018 HT_3 The recovery of 58P was also a SWAN find. cheers, Michael From: [email protected] <[email protected]> On Behalf Of Vladimir Bezugly via groups.io Sent: Friday, 11 April 2025 6:02 PM To: [email protected] Subject: Re: [comets-ml] C/2025 F2 (SWAN) + coordinate conversion check Hi Michael. If I correctly understood this - we all should to congratulate you with a TEN comet that you discovered in the SWAN data! So my congratulations to you with this milestone! Vladimir.

Good afternoon, everyone. How do I obtain map of constellation in SWAN, STEREO images? I've seen these several times but I don't know how to get them And also calculating approximate right ascension and declination. (also from SWAN) Regards,

Dear Vladimir and Michael Mattiazzo: I am *relieved* that CBAT 5538 provides the missing timeline and important details of all the independent discovery work carried out by not only the three of us in measuring the comet’s very coarse astrometry in SWAN, but the essential confirmation attempts undertaken by a small army of ground-based observers cued by our ephemerides. I was a bit crestfallen by the short shrift given in MPEC 2025-G102 to the importance of the discovery observations and measured astrometry by Vladimir, Michael and myself. (After 12+ manhours of back-and-forth with MPC by Bill Gray and myself, we were finally able to get SWAN astrometry accepted by MPC.) SWAN comet finders all know going in that we have no naming rights – that the comet will get a SWAN name designation, just as SOHO and STEREO comets are named after those respective spacecraft/instruments. Brian Marsden (R.I.P.) understood and appreciated the contributions of “citizen scientists,” and so he was supportive of at least publicly crediting these discovery efforts. I thought perhaps that MPEC 2025-G102 would follow the precedent of 2023-D49 which provided clear credit to Vladimir for the discovery of C/2023 A2 (SWAN) in its opening paragraph: https://minorplanetcenter.net/mpec/K23/K23D49.html This was the first time ever that SWAN astrometry actually appeared in an MPEC. But, alas, none of those discovery details were given in MPEC 2025-G102: https://minorplanetcenter.net/mpec/K25/K25GA2.html No mention of Vladimir, and indeed there would have been no mention of Michael Mattiazzo in the MPEC if not for his iTelescope follow up observations using U94. The 249 astrometry reported happens to be mine (due to the somewhat excruciating efforts of Bill Gray and myself mentioned above), but I should think Michael’s or Vladimir’s would have been equally valid (though perhaps missing the SWAN instrument details), and their astrometry was reported to CBAT up to two days prior to mine. The bottom line is that we need a better reporting and acknowledgment system. Comets first found in SWAN data are quite rare – now just 21 of them since 1997 – and at least a couple of those discoveries reverted to prior designations (e.g. P/2018 HT3). The SWAN experts who do this work (are there even a dozen of us alive?) have surely earned some recognition for their hundreds if not thousands of hours’ work per actual comet discovery. --Rob From: [email protected] <[email protected]> On Behalf Of Vladimir Bezugly via groups.io Sent: Tuesday, April 8, 2025 5:53 PM To: [email protected] Subject: EXTERNAL: [comets-ml] C/2025 F2 (SWAN) Hi All. Just now was released CBET 5538 and SWAN25F = C/2025 F2 (SWAN)! My congratulations to Michael and Robert! Great job guys! I am also grateful to each and everyone who took part in this case - I proud that I can be a part of so good and so powerful astro-community. Also many thanks to Daniel Green and to CBAT and MPC staff. Vladimir.

Hi all, If you didn't check the WGSBN website, just to inform you that the WGSBN has assigned names to three comets that were up to now unnamed: - C/2015 K7 (COIAS) - P/2023 S1 (PANSTARRS) - 471P/LINEAR-Lemmon Adrien

I used that PCCP ephemeris https://www.minorplanetcenter.net/iau/NEO/pccp_tabular.html (clicking SWAN25F and "Get ephemerides") and for April 7d 00UT it gives: ra/dec 23 32 41.7 / +25 30 14 but Bill Gray's projectpluto.com ephemeris on: https://www.projectpluto.com/neocp2/mpecs/SWAN25F.htm#eph gives ra/dec 23 32 05.740 / +25 24 29.49 which is an error of 9.94 arcminutes! (8.12' in RA, and 5.74' in DEC) I am assuming Bill's site is correct as it agreed with a photo I took a couple of mornings ago. So, what's with PCCP ephemerides anyone know!? On Sunday 6 April 2025 at 13:05:52 IST, Nick James <comets@...> wrote: It is currently on the PCCP. Just select SWAN25F here: https://www.minorplanetcenter.net/iau/NEO/pccp_tabular.html and you can generate an ephemeris for your location. Nick.

I've been using the Harvard CBAT site for many years as one source of information on transient phenomena but the website has been down for several months now. https://www.cbat.eps.harvard.edu/ Does anyone know what is going on? Thanks, Bob

Can somebody please give me the coordinates of the new comet? I tried to find the ephemeris, but failed. Regards,