May this be the subsequent nice comet? To make certain, these phrases have been mentioned numerous instances earlier than. In a clockwork sky, how comets will carry out is at all times the good wildcard. Comets from Kohoutek to ISON have did not dwell as much as expectations, whereas others like W3 Lovejoy took us all unexpectedly. However a discovery this previous weekend has message boards abuzz, as an incoming sungrazer may placed on a present proper round Halloween.

Anatomy of a Sungrazer

The invention involves us from the prolific Asteroid Terrestrial-impact Final Alert System (ATLAS), which first noticed the comet on the evening of September 27^th. The preliminary designation of the comet was A11bP7I. The comet now has an official designation: C/2024 S1 ATLAS. This was introduced on October 1^st, within the Worldwide Astronomical Union’s Central Bureau for Astronomical Telegram’s message 5453.

The extremely eccentric hyperbolic orbit of the comet suggests it’s a member of the Kreutz household group of sungrazer comets. Most of those comets are doomed for destruction at perihelion, however there have been a number of exceptions through the years. These sungrazers which have survived have gone on to turn into nice comets.

May C/2024 S1 ATLAS do the identical?

Comet Caveats

Now, a number of caveats are so as. Astronomers discovered S1 ATLAS at +12^th magnitude, 1.094 Astronomical Items (AU) from the Solar. It may properly be the case that it merely had an outburst proper when it was first noticed, and will in actual fact be smaller and fewer energetic than it appears. What we want are extra observations over the subsequent few weeks.

“It’s early days, so I believe the prudent method is to reasonable our expectations after which be ‘pleasantly shocked’ later,” astronomer Karl Battams (U.S. Naval Analysis Laboratory) instructed Universe In the present day. “That mentioned, there’s clearly the potential for this to be a really thrilling comet. The most effective analog now we have is comet Lovejoy in 2011, which was found simply a few weeks from perihelion, versus this one which is almost a month away.”

The comet reaches perihelion on October 28^th, 0.0082 AU from the Solar. That’s 762,600 miles from photo voltaic heart, simply 330,600 miles from the floor of the Solar. The photo voltaic radius is about 432,000 miles. As at all times appears to be the case, southern hemisphere observers will get a greater view of the comet main as much as perihelion in mid-October because it approaches the Solar by means of the constellation Hydra. The comet will probably be seen low to the east at daybreak, and ‘may’ break +6^th magnitude within the remaining week of October. The comet passes 0.306 AU from the Earth on October 23^rd after which, issues may begin to get attention-grabbing.

Prospects for Sungrazer A1 ATLAS

As of scripting this, greatest estimates for peak magnitudes for comet S1 ATLAS high out at -7—assume a vibrant daytime comet, however very near the Solar—although -1^st magnitude or so might be extra conservative.

Northern hemisphere viewers may get greatest views of the comet low to the east at daybreak after perihelion… if it survives.

“This Kreutz-group comet gained’t move fairly as near the Solar as W3 Lovejoy, so it’s not unreasonable to guess that it’s going to support its survival potential.” Says Battams. “Assuming so, it is likely to be briefly seen to northern hemisphere observers very low within the early morning (in) southeast skies after perihelion, however it might require good viewing circumstances (a transparent, low horizon)… and gained’t dangle round there for lengthy.”

The comet enters the Photo voltaic Heliospheric Observatory (SOHO’s) LASCO C2/C3 subject of view on October 26^th, and exits on the 29^th. It’s unusual to assume: previous to SOHO’s launch in 1995, astronomers knew of lower than a handful of sungrazer comets. Now, because of the mission, we all know of 5,065 sungrazing comets and counting.

New sticky: I not often tweet lately, primarily b/c a lot of the enjoyable folks have left. ? However I nonetheless pop in from time-to-time, and can submit about thrilling comet or Solar stuff.
As at all times, any photos/information I submit are from 100% public sources, and all opinions are solely mine. pic.twitter.com/OeQRia2ppU

— Karl Battams (@SungrazerComets) October 2, 2024

Traditional Sungrazers of Yore

2011’s sungrazer W3 Lovejoy survived a passage simply 87,000 miles from the floor of the Solar… Comet ISON, nevertheless, didn’t survive a 0.001244 AU, 116,000 mile floor move at perihelion on U.S. Thanksgiving Day 2013.

Lengthy-time comet watchers will bear in mind sungrazer Ikeya-Seki, which survived a 280,000 mile move (just a bit over the Earth-Moon distance) from the floor of the Solar. That comet went on to dazzle observers in 1965.

“What I’ll say is that I’m very excited on the ‘prospect,’ and will probably be watching the evolution of this extraordinarily intently over the subsequent couple of weeks.” says Battams. “I believe by mid-October we’ll be capable to state some details with much more certainty.”

It looks like good comets at all times are available in pairs…bear in mind Hale-Bopp and Hyakutake within the late 90s? We (lastly) caught sight of comet C/2023 A3 Tsuchinshan-ATLAS this morning from right here in Bristol, Tennessee, wanting like a fuzzy ‘star’ with a brief tail within the brightening twilight low to the east, peeking out between pine bushes.

We’re cautious for now in the case of S1 ATLAS. However bear in mind: comets by no means learn predictions… and S1 ATLAS may properly shock us.