{"id":789881,"date":"2024-10-03T13:27:52","date_gmt":"2024-10-03T18:27:52","guid":{"rendered":"https:\/\/spaceweekly.com\/?p=789881"},"modified":"2024-10-03T13:27:52","modified_gmt":"2024-10-03T18:27:52","slug":"could-a-new-sungrazer-comet-put-on-a-show-at-the-end-of-october","status":"publish","type":"post","link":"https:\/\/spaceweekly.com\/?p=789881","title":{"rendered":"Could a New Sungrazer Comet Put on a Show at the End of October?"},"content":{"rendered":"


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Could this be the next great comet? To be sure, these words have been said lots of times before. In a clockwork sky, how comets will perform is always the great wildcard. Comets from Kohoutek to ISON have failed to live up to expectations, while others like W3 Lovejoy took us all by surprise. But a discovery this past weekend has message boards abuzz, as an incoming sungrazer could put on a show right around Halloween.<\/p>\n

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Anatomy of a Sungrazer<\/h2>\n

The discovery comes to us from the prolific Asteroid Terrestrial-impact Last Alert System (ATLAS), which first spotted the comet on the night of September 27th<\/sup>. The initial designation of the comet was A11bP7I. The comet now has an official designation: C\/2024 S1 ATLAS. This was announced on October 1st<\/sup>, in the International Astronomical Union\u2019s Central Bureau for Astronomical Telegram\u2019s message 5453. <\/p>\n

The orbit of Comet C\/2024 S1 ATLAS. Credit: NASA\/JPL.<\/figcaption><\/figure>\n

The highly eccentric hyperbolic orbit of the comet suggests it\u2019s a member of the Kreutz family group of sungrazer comets. Most of these comets are doomed for destruction at perihelion, but there have been a few exceptions over the years. Those sungrazers that have survived have gone on to become great comets.<\/p>\n

Could C\/2024 S1 ATLAS do the same?<\/p>\n

Comet Caveats<\/h2>\n

Now, a few caveats are in order. Astronomers found S1 ATLAS at +12th<\/sup> magnitude, 1.094 Astronomical Units (AU) from the Sun. It could well be the case that it simply had an outburst right when it was first spotted, and could in fact be smaller and less energetic than it seems. What we need are more observations over the next few weeks.<\/p>\n

\"Comet\"
Comet C\/2024 ATLAS imaged shortly after discovery. Credit: Michael Jaeger. <\/figcaption><\/figure>\n

\u201cIt\u2019s early days, so I think the prudent approach is to moderate our expectations and then be \u2018pleasantly surprised\u2019 later,\u201d astronomer Karl Battams (U.S. Naval Research Laboratory) told Universe Today<\/em>. \u201cThat said, there\u2019s clearly the potential for this to be a very exciting comet. The best analog we have is comet Lovejoy in 2011, which was discovered just a couple of weeks from perihelion, versus this one which is nearly a month away.\u201d<\/p>\n

\"Comet\"
Comet S1 ATLAS imaged on September 28th. Credit: Filipp Romanov. <\/figcaption><\/figure>\n

The comet reaches perihelion on October 28th<\/sup>, 0.0082 AU from the Sun. That\u2019s 762,600 miles from solar center, just 330,600 miles from the surface of the Sun. The solar radius is about 432,000 miles. As always seems to be the case, southern hemisphere observers will get a better view of the comet leading up to perihelion in mid-October as it approaches the Sun through the constellation Hydra. The comet will be visible low to the east at dawn, and \u2018could\u2019 break +6th<\/sup> magnitude in the final week of October. The comet passes 0.306 AU from the Earth on October 23rd<\/sup> after which, things could start to get interesting.<\/p>\n

Prospects for Sungrazer A1 ATLAS<\/h2>\n

As of writing this, best estimates for peak magnitudes for comet S1 ATLAS top out at -7\u2014think a bright daytime comet, but very<\/em> close to the Sun\u2014though -1st<\/sup> magnitude or so is probably more conservative.<\/p>\n

Northern hemisphere viewers might get best views of the comet low to the east at dawn after perihelion\u2026 if it survives.<\/p>\n

\"Dawn\"
Looking low to the east at dawn on Halloween morning. Credit: Starry Night. <\/figcaption><\/figure>\n

\u201cThis Kreutz-group comet won\u2019t pass quite as close to the Sun as W3 Lovejoy, so it\u2019s not unreasonable to guess that it will aid its survival potential.\u201d Says Battams. \u201cAssuming so, it might be briefly visible to northern hemisphere observers very low in the early morning (in) southeast skies after perihelion, but it would require good viewing circumstances (a clear, low horizon)\u2026 and won\u2019t hang around there for long.\u201d<\/p>\n

\"SOHO
A simulation of Comet A1 ATLAS in SOHO\u2019s field of view. Credit: Starry Night. <\/figcaption><\/figure>\n

The comet enters the Solar Heliospheric Observatory (SOHO\u2019s) LASCO C2\/C3 field of view on October 26th<\/sup>, and exits on the 29th<\/sup>. It\u2019s strange to think: prior to SOHO\u2019s launch in 1995, astronomers knew of less than a handful of sungrazer comets. Now, thanks to the mission, we know of 5,065 sungrazing comets and counting. <\/p>\n

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New sticky: I rarely tweet these days, mainly b\/c most of the fun people have left. ? But I still pop in from time-to-time, and will post about exciting comet or Sun stuff.
As always, any images\/data I post are from 100% public sources, and all opinions are solely mine. pic.twitter.com\/OeQRia2ppU<\/a><\/p>\n

\u2014 Karl Battams (@SungrazerComets) October 2, 2024<\/a><\/p>\n<\/blockquote>\n

Classic Sungrazers of Yore<\/h2>\n

2011\u2019s sungrazer W3 Lovejoy survived a passage just 87,000 miles from the surface of the Sun\u2026 Comet ISON, however, did not survive a 0.001244 AU, 116,000 mile surface pass at perihelion on U.S. Thanksgiving Day 2013.<\/p>\n

Long-time comet watchers will remember sungrazer Ikeya-Seki, which survived a 280,000 mile pass (just a little over the Earth-Moon distance) from the surface of the Sun. That comet went on to dazzle observers in 1965. <\/p>\n

\"Ikeya
Comet Ikeya-Seki. Credit: James W. Young\/TMO\/JPL\/NASA.<\/figcaption><\/figure>\n

\u201cWhat I will say is that I am very excited at the \u2018prospect,\u2019 and will be watching the evolution of this extremely closely over the next couple of weeks.\u201d says Battams. \u201cI think by mid-October we\u2019ll be able to state some facts with a lot more certainty.\u201d<\/p>\n

It seems like good comets always come in pairs\u2026remember Hale-Bopp and Hyakutake in the late 90s? We (finally) caught sight of comet C\/2023 A3 Tsuchinshan-ATLAS this morning from here in Bristol, Tennessee, looking like a fuzzy \u2018star\u2019 with a short tail in the brightening twilight low to the east, peeking out between pine trees.<\/p>\n

We\u2019re cautious for now when it comes to S1 ATLAS. But remember: comets never read predictions\u2026 and S1 ATLAS could well surprise us.<\/p>\n

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