Tootfinder

This image shows the #Kreutz comet C/2026 A1 (MAPS) "on a stack build from (star subtracted) difference images [from the PUNCH satellites] between March 26, 7:28 UT and 13:36 UT. The visible tail extends to about 6 degrees" - but the recent brightness surge has levelled off at about 8.8 mag.: https://groups.io/g/comets-ml/message/35114

The uncertain brightness and tail(s) development of #Kreutz #comet C/2026 A1 (MAPS) is one thing - see the curves in https://astro.vanbuitenen.nl/comet/2026A1 and https://aerith.net/comet/catalog/2026A1/2026A1.html for guesses and https://cobs.si/obs_list?id=2688 for the current value which is ~8.5 mag. - but the viewing geometry is the other: here it is for 51.5° North (my place Bochum) and 22.5° South (Windhoek) as the view is much better from the southern hemisphere.
The table first gives the elongation (angle between comet and Sun in the sky) and the phase angle (the angle Sun - comet - Earth) which nearing 180° can lead to significant boost of brightness by forward scattering on dust.
And this is followed by the altitude of the comet at the solar depressions given in the top line, for Bochum and Windhoek: sunset and end of civilian twilight and for the latter also the end of nautical and astronomical twilight, i.e. the onset of night. Also of importance is the angle of a hypothetical dust tail (simulated in https://hdr-astrophotography.com) after perihelion, also much better in the South: https://britastro.org/section_news_item/c-2026-a1-maps-a-kreutz-group-sungrazer - but first MAPS has to survive the latter *and* release a lot of dust at the right time ...

Whoa, what has the #Kreutz comet C/2026 A1 (MAPS) done now?!? Photometry from images by the outer corona observing satellite constellation PUNCH - by Thomas Lehmann; https://groups.io/g/comets-ml/message/35106 - shows a sudden increase in coma brightness ... whatever that means for the apparently quite fragile nucleus. PUNCH can follow the comet closer to the Sun than ground-based observers who will lose sight by month's end.

Two attempts to simply extrapolate the brightness of #Kreutz comet C/2026 A1 (MAPS) from what happened in the past few weeks, from all visual observations reported to COBS (left) and from all CCD observations of the past month which would have the brightness climb a bit faster. But as the previous post in the thread has shown even in the geometrically preferred southern hemisphere MAPS is lost in twilight from about March 30 to April 7 - and even in the optimistic model the comet has reached only 6th magnitude when it is lost and is down again to 5th when it is recovered: unless something drastic would happen *all* hope for an interesting show rests on a possible post-perihelion dust tail. Good luck ...

Preliminary Nucleus Size Estimate for #Kreutz Sungrazer C/2026 A1 (MAPS): https://iopscience.iop.org/article/10.3847/2515-5172/ae5220 -> "JWST imagery of the approaching Kreutz sungrazer C/2026 A1 (MAPS) appears sufficient to distinguish the comet’s nucleus from the surrounding dust. Coma model fitting indicates the morphology is compatible with a ∼0.4 km diameter nucleus—likely larger than those of the minor Kreutz fragments routinely discovered with coronagraphs, and comparable to or slightly smaller than that of C/2011 W3 (Lovejoy). However, since C/2026 A1 is the only Kreutz sungrazer whose nucleus has been directly observed, these comparisons should be treated with caution" -> https://groups.io/g/comets-ml/message/35035 / https://scicomm.xyz/@qicheng@cometary.org/116245251072721081

Whatever eagerly awaited #Kreutz #comet C/2026 A1 (MAPS) is up to - see also https://groups.io/g/comets-ml/topic/118409957 and https://nitter.net/JAtanackov/status/2035718257060036738 and https://scicomm.xyz/@qicheng@cometary.org/116262858373488354 - less than two weeks from perihelion, it has developed a long plasma tail now: https://www.facebook.com/photo/?fbid=25816609931372735 (Rhemann & Jäger yesterday with a 12 inch telescope; full and detail).

"The most recent orbital computations make it increasingly likely that the object [the new #Kreutz comet MAPS] is a fragment of one of the comets observed by Ammianus Marcellinus in AD 363, thereby strengthening evidence in support of the contact-binary hypothesis of the Kreutz system," writes Zdenek Sekanina in https://arxiv.org/abs/2602.17626: "In this context, the comet is the only second-generation fragment of Aristotle's comet that we are aware of to appear after the 12th century. It does not look like a major fragment, but rather like an outlying fragment of a much larger sungrazer."

So the new #Kreutz #comet #MAPS is *still* following the constant rapid rise in brightness it has shown since discovery: a dumb extrapolation - https://cobs.si/analysis/?comet=2688&from_date=2026-01-15 00:00&to_date=2026-04-30 00:00&observation_type=V&observation_type=C&plot_x_value=1&plot_y_value=1&fit_option=1&exclude_faint=on&exclude_issue=on&observer=&association=&country=&compare_values=compare - has it get 10,000-times brighter than the Sun at its extremely close perihelion which makes so sense at all, of course, physically.
"It must therefore be assumed that this increase in activity will level off significantly in the near future," writes https://fg-kometen.vdsastro.de/koj_2026/c2026a1/26a1eaus.htm: "More likely are parameters m m0=12.0 mag / n=4 (or even lower), which would still result in a (very short-term) maximum brightness of about –9 mag (but this would probably still be significantly too bright) – always assuming that the comet survives its perihelion passage unscathed."
For other views see http://www.cbat.eps.harvard.edu/iau/cbet/005600/CBET005663.txt and https://arxiv.org/abs/2602.17626 and https://www.facebook.com/photo?fbid=10236580364221799 and https://cometografia.es/cometa-kreutz-2026-a1-maps-analisis/ - and the actual brightness is tracked at https://cobs.si/obs_list?id=2688 where it has reached ~11.5 mag. now.

The #Kreutz #comet #MAPS "has become more than 1 mag brighter between March 6 and 9" and stands at 10.5 mag. right now: https://groups.io/g/comets-ml/message/35019 and https://www.facebook.com/photo/?fbid=2374472359736249 with the latest picture by Jäger & Rhemann here - less than 4 weeks til perihelion, and the brightness continues to rise with a strong n~8 ...

At 18:15 UTC - 6 hours before the solar eclipse for Artemis II begins - the remains of #Kreutz comet MAPS are hard to see (near the edge of the field in the 2 o'clock position) even with a lot of contrast boosting of the https://ccor.nrl.navy.mil/ccor_realtime/last_image_MinBckgnd.png images.

The detached remnant dust tail of #Kreutz ex-comet MAPS is slowly fading in CCOR-1 - check out https://ccor.nrl.navy.mil/realtime-movie for a *wild* animation - but on the other hand showing lots of striations. These three images cover a span of 7 hours today. Will anyone be able to spot it from the ground .... or the Artemis II crew exactly 30 hours from now when their solar eclipse begins? Fingers crossed and ISO high ... ;-)

The coma of #Kreutz comet MAPS has now vanished behind the occulter in CCOR-1 while in the delayed LASCO images it is getting increasingly dimmed by the coronagraph system which has to suppress more light closer to the Sun.

Six hours till perihelion for #Kreutz comet MAPS ... and in the CCOR-1 view from 7:45 UTC it's still doing great!

The dust cloud born out of the demise of #Kreutz comet MAPS yesterday continues to evolve dramatically in https://ccor.nrl.navy.mil/ccor_realtime/last_image_MinBckgnd.png images, here from 0:45 and 2:30 UTC Sunday - most think it's a former dust tail the comet formed hours before perihelion, with particles being pushed away from the Sun by radiation pressure far enough that they survived their personal perihelia while the comet itself did not. At least for this coronagraph the surface brightness looks pretty high ...

How #Kreutz comet C/2026 A1 (MAPS) is doing: LASCO and CCOR images from 19:30 and 20:00 UTC respectively. Under 18 hours til perihelion now ...

The #Kreutz comet MAPS is now also in the field of view of the coronagraph CCOR-1: help yourself to the latest images at https://ccor.nrl.navy.mil/ccor_realtime/last_image_MinBckgnd.png (15 minute cadence). What SOHO's LASCO C3 and PUNCH's NFI see and what it all means I've just summarized the bottom of https://skyweek.wordpress.com/2026/04/01/artemis-ii-vor-dem-start-maps-vor-dem-perihel/ with the still growing thread https://groups.io/g/comets-ml/topic/118640744 as the major source - in a nutshell there is still some life in this sungrazer (25 hours til perihelion!) and no evidence that it's beginning to fall apart which it will certainly do at one point.

Progress report for #Kreutz come C/2026 A1 (MAPS) as it marches towards the Sun in the LASCO and CCOR coronagraphs where it is brightening: https://groups.io/g/comets-ml/message/35184 - at https://ccor.nrl.navy.mil/realtime-movie you can watch an animation of the most recent CCOR images.

Twelve hours to go till #Kreutz comet C/2026 A1 (MAPS) reaches its perihelion - and it's still healthy for CCOR-1 in this image from 1:45 UTC today. Fresh ones at https://ccor.nrl.navy.mil/ccor_realtime/last_image_MinBckgnd.png every 15 minutes - and (uplifting) assessments of what's going on in https://www.facebook.com/groups/633346904255340/posts/2004738737116143 and https://www.facebook.com/photo/?fbid=10233680923429250

The #Kreutz comet C/2026 A1 (MAPS) is now in the field of view of SOHO's LASCO C3, https://soho.nascom.nasa.gov/data/realtime/c3/1024/latest.gif - and has only 4th magnitude or so. Here is how Lovejoy entered in 2011 which eventually did great: https://nitter.net/JAtanackov/status/2039812615988224394#m. Meanwhile here is the light curve of MAPS from PUNCH: https://groups.io/g/comets-ml/message/35159

Exactly 24 hours from now - at 0:35 UTC on 7 April - the total eclipse for the #ArtemisII crew will begin ... will they see / be able to photograph the fading detached dust tail of #Kreutz comet MAPS imaged here by #ZodiacalLight / potential dust hovering over the lunar limb might record it as well.

This afternoon UTC #Kreutz comet C/2026 A1 (MAPS) - which has been tracked in recent days with PUNCH and STEREO and is still in one piece, it seems - will enter the field of view of the coronagraph LASCO C3 on SOHO (the brown background; arrow): comparisions with earlier sungrazers in the same instrument will be telling.