Karl Battams

Fine-scale structure in cometary dust tails II: Further evidence for a solar wind influence on cometary dust dynamics from the analysis of striae in comet C/2011 L4 Pan-STARRS Striated features, or striae, form in cometary dust tails due to an as-yet not fully constrained process or processes. Using STEREO-B SECCHI HI-1 inst…

Yeah, that paper and this one - www.sciencedirect.com/science/arti... - give some details (I was co-author on both). In short: comet loses dust chunk; chunk falls apart; chunks of the chunk fall apart; chunks of the chunks of the chunk fall apart... etc... aka "cascading fragmentation".

What a beauty! This is comet C/2024 G3 (ATLAS) passing through the field of view of the LASCO C3 coronagraph.

It wasn't for certain whether it would survive it's closest approach to the sun on January 13th, but it did and delivered us a spectacular show!

#comet #C2024G3 🔭

Individual curves are here: lasco-www.nrl.navy.mil/index.php?p=... I could probably plot them... As for the original purpose of them... 🤷 I can ask some of the retirees what the thinking was.

PUNCH images would look a lot like C3 Clear, but with a wider fov.

Yes!! Plus... SOHO was actually "lost" for ~3 months in '98, spinning out of control, and effectively frozen solid. The recovery was nothing short of miraculous! A great account of it can be found in "Saving SOHO", linked via: soho.nascom.nasa.gov/about/Recove...

Yep, that processing is equally fantastic. It's all fantastic! 😊

Here's the last frame in the sequence, minus the mp4/streaming compression. Still a tad over-exposed in my processing, but certainly much better than the default processing we see on the SOHO site.

As many have pointed out, the LASCO images on the SOHO website are saturated. So this is the result of my own algo for processing them.

And I will echo my sentiments from yesterday: This. Comet. Is. RIDICULOUS! 🤩😍 ☄️🔭☀️

Yeah there's a lot going on in these images - I don't want to speculate too much on exactly what. This is a particularly special comet for sure, though. And we will absolutely miss LASCO when it's gone ☹️

AAARRGHHH!!!!! 🤬😖😫

Yes it should. Sigh.

I really, REALLY can't get over just how beautiful this comet is in our LASCO images! I mean, I've seen more than a handful of comets in this data over the years (~5,200 to be exact - not that I'm counting...) But I've really gotta say... this might be the pick o' the bunch right here. WOW 😱😍☄️☀️🔭

C/2024 G3 (ATLAS) Jan 13.715, 2025 UT- Processed from images courtesy of SOHO (Solar and Heliospheric Observatory). An RGB image was created by mapping the color channels to images acquired with different filters using SOHO's LASCO C3 camera.

No problem! The wikipedia article is pretty good: en.wikipedia.org/wiki/C/2024_...

Be skeptical of media sources (some are great, others less so), and always feel free to reach out with questions!

This has me really excited for the comet viewing we will do with PUNCH once we launch in a few weeks. Our inner field of view limit matches LASCO C3, but our outer field of view extends out six times farther — to 45 degrees from the Sun! ☀️🛰️🔭

☹️ Worth a shot! One day, hopefully we'll have a sungrazer we can all see in the daytime!

That's still unknown. It's possible, but the LASCO cameras don't have the kind of resolution to tell us that. We might have clues in the next few days... Maybe...

Yeah I don't think it's quite naked eye. It's like vmag -2.5 or so. LASCO images look amazing tho!

I've seen several images from folks capturing it during the daytime, so it is *technically* possible! Just of course take all the kind of precautions you'd expect to take when pointing magnifying optics near the Sun...😵😬 And report back if you get it! 😊

Truly a stunning tail on this comet, as seen by our @esa.int / NASA SOHO/LASCO camera! 😍☀️🔭☄️

Short animation of C/2024 G3 (ATLAS) in the Blue filter on our ESA/NASA SOHO/LASCO C3 camera. ☀️🔭 Seeing lots of beautiful striations in the tail! 😍

Four views of comet ATLAS today: from soho.nascom.nasa.gov/data/realtim... (SOHO LASCO C3 at 18:54 UTC today), x.com/dermuehle/st... (dito; deep red filter -> almost no saturation), www.facebook.com/groups/32578... (from the ISS) and www.facebook.com/photo/?fbid=... (from the ground, in daytime).

We have another super bright comet (C/2024 G3 Atlas) making an appearance in LASCO C3 imagery! ☀️☄️

Comet

The Comet Observer’s Data Base (COBS) currently lists the comet at magnitude -3.7 ‘with a bullet’. Petr Horálek snapped this view of the comet at sunrise on January 11th over Spisske Podrhadie, Slovakia:

Zoomed in. No processing at all

Comet G3 ATLAS looking great in the raw Blue filter LASCO C3 images! ☀️🔭

CCD image of C/2024 G3 (ATLAS) taken at daytime on Jan 11, 2025, by Nick James, Chelmsford, UK. Positive (top) and negative (bottom) noisy image with a comet and a short tail clearly visible.

The comet has been imaged during the day by Nick James, Chelmsford, UK. See groups.io/g/comets-ml/...
Elongation ~8°. Max mag expected on Jan 12/13.
Note: Never look directly at the Sun with the naked eye or with any unfiltered optical device, such as binoculars or a telescope!
☄️🔭 #CometWatch

G3 ATLAS is now entering LASCO C3! ☀️🔭🛰️ Judging by the saturation spikes, it's at the upper end of our brightness estimates (maybe mag -1 or so? Just eyeballing, so could be off on that). Anyway, follow along over the next few days: soho.nascom.nasa.gov/data/realtim...

Qicheng - do you just need the SOHO spice kernel for 2025? That's here: soho.nascom.nasa.gov/data/ancilla...

Yep, the ground station was affected (safety-wise, not directly) so the SOHO telemetry couldn't be collected. My understanding is that we should see data flowing again today. Unclear if we lost any data tho

Still don't know what to expect with G3. I suspect (as some others do) it has disrupted, and likely won't fare well. In principle, it could reach vmag -3 or so, but that depends very much on its current Level of Chunkiness:
~one chunk: 😀🥳
a few bigs chunks: 😐
lots of chunks: ☹️
bazillion chunks: 😭💀
🤷

Transits through the SOHO LASCO C2 and C3 fields of view in 2025 are now posted: sungrazer.nrl.navy.mil/transits_2025

Huge thanks as always to Sungrazer Project contributor (superstar!) Worachate Boonplod for compiling the list/graphic.

Of note: C/2024 G3 (ATLAS) enters LASCO C3 on Jan 11! ☀️🔭☄️