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Hello all, I managed to capture the remains of disintegrated comet C/2025 F2 SWAN. Attached image was taken on 2025 May 16 at 23:00UT using a remote telescope in Chile, ASAN250 f/3.8 + ASI6200mm 4x60sec. FOV 30'. North right. The debris field stretches at least 10' NE from the ephemeris position and appears of approximate magnitude 13-14. cheers, Michael

Hi all, Comet 29P/Schwassmann-Wachmann is most likely in a strong outburst. I imaged this comet earlier today and noticed a condensed inner coma of 0.4' in diameter with classic outburst appearance. Outer coma is large and very diffuse. Total magnitude measured is m1=12.4:, dust production rate is huge Af(Rho)=20336±678 cm. Comet 29P/Schwassmann-Wachmann 2025 May 16.20 UT inner coma dia.=0.4' m1=13.7; outer coma dia.=&4.1' m1=12.4: (m2=14.4)... [T11] 0.51-m f/4.5 Corrected Dall-Kirkham + CCD... iTelescope observatory, U94 (remotely from Great Basin Desert, Beryl Junction, Utah, USA) Image is attached. Please, confirm! -- best regards, Taras

On the evening of 2025 April 29 Comet C/2025 F2 (SWAN) had a 9' long tail at a position angle of 349 degrees from where the comet coma use to be before the comet disintegrated. On the evening of 2025 May 2 the tail was not evident beyond the disintegrated debris field in the 4.8' wide aperture diameter circle, at least not in the 50mm f/5 Refractor and IMX462 camera. Using the 4.8' wide aperture diameter circle to encompass the major part of the disintegrated comets debris field the comet remnants magnitude was 8.5 on April 29 and 8.6 on May 2. There were no stars brighter than magnitude 15 in either 4.8' wide aperture diameter circle and the faintest stars in all images was about magnitude 14. The images were taken at an altitude of 4 to 5 degrees just as twilight was fading and before the comet sank into the atmospheric haze.

Possible detection of C/2025 F2 (SWAN) on April 28.86: https://britastro.org/observations/observation.php?id=20250429_063941_2990db2ceeed4e3a A very noisy image taken in very bright twilight but there is a faint patch of material at the right location. Nick James. BAA

Hi all FYI. Earth is now crossing the orbital plane of Ghost comet C/2024 G3 ATLAS. This Image was taken on 2025 April 30 at 09:15UT using a remote telescope ITEL-T70 Chile 135 mm f/3.5 Samyang Lens + CMOS. 10x60sec. FOV 7 deg. North right. The dust trail in this image, viewed edge-on, is at least 4 degrees long in PA13. Star above centre is Psi Phe. Delta Phe is below left. Total magnitude of the comet is difficult to ascertain, (approx mag 10) but visual attempts are encouraged. Best situated for southern observers in the morning sky. Despite its disintegration in January, it keeps on giving. ? Cheers, Michael

Hello, a recent photo of the remnants of comet C/2025 F2 (SWAN) taken by BBO on 2025.04.29 https://www.danilopivato.com/solar_system/comets/c2025_f2_swan/c2025_f2_swan.html Best, BBO

Dear all, This may well be a false alarm (perhaps caused by fortuitously placed noise), but, for what it’s worth: This asteroid in a distinctly cometary orbit (e = 0.74, q = 1.80 AU, P = 17.8 years) is returning to perihelion in June. I have been taking some occasional images of it with LCO to see if it might be exhibiting cometary activity. In a set of images I took yesterday with one of the 1-m scopes at LCO-Siding Spring there is, possibly, a very faint wisp of material extending roughly towards the north-northwest. I’m attaching both positive and negative versions of a stacked image (total exposure 15 minutes), approximate dimensions 2x2 arcminutes; I have *not* enhanced the contrast. I am certainly not convinced that this is real, but I’m not entirely convinced that it isn’t real, either. Anyway, for anyone who is interested and who has suitable equipment, feel free to have a go at this object. Even if this is a false alarm, it is still five months away from perihelion passage, so the development of cometary activity is certainly possible. Note that the viewing geometry at perihelion is not very favorable (elongation 38 degrees). Meanwhile, there are a couple of similar objects that are also worthy of attention. 2017 MB1, which was discussed in this forum within the fairly recent past, passed through perihelion just before the end of December and is now emerging into the evening sky, although the viewing geometry is not especially favorable. It passes 0.42 AU from Earth in early February. (6144) Kondojiro passes through perihelion in early June, and the viewing geometry is quite favorable (opposition is in early-mid April). I took some images during last year’s opposition but didn’t detect anything cometary, and I’ll probably start some new attempts shortly. The perihelion distance (3.06 AU) is, unfortunately, probably too large to stimulate much in the way of cometary activity . . . but one never knows . . . Sincerely, Alan

Hello everyone, on the evening of April 26th an attempt was made to capture what remains of the comet. The shooting conditions were extreme: object very low on the horizon (h = < 4°) passing clouds, little light time available. In each case 22 frames were taken with 20-second exposures each, the 10 best were selected. The attached image in the red circle indicates the position of the comet. Danilo Pivato (BBO)

Hi all, since its last outburst, it seems that comet c/2025 f2 SWAN isn’t brightening anymore. I observed it visually a few times last week and every time it was about the same brightess, but actually I don’t see any evidence of a possible fragmentation, so I don’t understand what’s happening to this object. It reminds me the behaviour of c/2024 s1 ATLAS. Could someone explain this unusual behaviour? Cheers, Erik

Dear all, I’d like to call attention to this object that was discovered by Pan-STARRS back in early March (MPEC 2025-F45). It’s traveling in an orbit typical for a Jupiter-family comet, i.e., P ~ 6.2 years, q ~ 0.68 AU, e ~ 0.80, T_J ~ 2.5. Perihelion passage is on June 19. Some Pan-STARRS observations from the previous return in 2019 have apparently been identified, the earliest of these being over six months past perihelion. In looking over its past, I see that the current return is, by far, the best one since the beginning of the 20th Century (I didn’t look at anything earlier than that). In fact, the current return is the first one in which the object has been accessible at any time close to perihelion since at least the 1950s. It has made a handful of somewhat close approaches to Jupiter (1.0 – 1.4 AU) since that time, and in the meantime it made three very close approaches to Venus (0.04 to 0.06 AU) between 2007 and 2019. On the current return it passes 0.23 AU from Earth on May 9, and passes just over three degrees from the north celestial pole three days later. (Unfortunately, the moon is full on May 12.) After that it remains accessbile in the morning sky, albeit at a somewhat small elongation, but even at perihelion will be at an elongation of 39 degrees. Since it is interior to Earth’s orbit it will be at a somewhat high phase angle, the maximum of 130 degrees occurring at the beginning of June, and still at 110 degrees at perihelion. I’ve been taking occasional images of it via LCO, the most recent being last night with the 1.0-meter scope at LCO-McDonald. Thus far, including last night, the appearance has been completely stellar. If it remains inactive it will be difficult to observe during the final run-up to perihelion, especially given the high phase angle. But if it should happen to become active it may remain detectable up through perihelion, and if there is any significant dust production the high phase angle might allow for some forward scattering enhancement. In any event, it’s worth keeping an eye on this object. And, for what it’s worth, the next return, in 2031, is even better, at least for those in the southern hemisphere: after perihelion passage in late August it passes just 0.14 AU from Earth in early October, and then just over four degrees from the south celestial pole a few days later. It will be at a fairly high phase angle for several weeks after perihelion (maximum 138 degrees during the latter part of September). Sincerely, Alan

The Moon was 94% illuminated on the morning of 2025 April 15 UT, Comet C/2025 F2 (SWAN) was magnitude G=9.4 as calculated from 6x20 second images thru a green filter in an aperture diameter of 3.5'. The coma was 3' wide, the wavy tail in the image FOV was 53' long at a position angle of 309 degrees from the coma. The comet has been quiet the past week, with a brightness staying around magnitude 8.9 to magnitude 9.4, but the comet certainly does have a nice thin wavy tail that extends about twice as long as shown in this set of images.