Comet Tsuchinshan-ATLAS may be disintegrating

Efrain Morales captured this image of Comet A3 Tsuchinshan-ATLAS from Puerto Rico on July 8, 2024. Image via Efrain Morales/ Eddie Irizzary.

Comet Tsuchinshan-Atlas my be disintegrating

Observers around the world have been waiting for the next great comet to become visible to the unaided eye, and many thought Comet Tsuchinshan-ATLAS might be it. Discovered in early 2023, the comet had the possibility of brightening substantially around the time of its closest approach to Earth and the sun this fall. However, as Comet C/2023 A3 Tsuchinshan-ATLAS has been approaching the inner solar system, it should have been brightening. But observers have not noticed an increase in brightness during the last three months. And now a new study suggests the cometary nucleus is fragmenting.

The paper’s author, Zdenek Sekanina, a Czech-American astronomer and comet expert at NASA’s Jet Propulsion Laboratory, said on July 8, 2024, the comet has entered an advanced phase of fragmentation. He said the end of Comet Tsuchinshan-ATLAS is inevitable.

However, comets are notorious for being erratic and unpredictable. So we will have to wait a few nights or weeks and see what happens to the comet next. If you have a small telescope, you can take a look for yourself. Check out the charts below.

Finder charts for Comet Tsuchinshan-ATLAS

If the comet is indeed breaking up and you still want to see it, you’ll have to dust off your telescope. According to The Sky Live, the current magnitude of the comet is 9.6, well beyond the range of the unaided eye. Here are some finder charts to help you track it down.

Star chart showing a glowing moon, red hashmarks to the lower right and the constellation Leo.
Here’s where to look for Comet Tsuchinshan-ATLAS on the evening of July 11, 2024. Face west shortly after sunset and use optical aid to search for the comet below the constellation Leo and to the lower right of the moon. Image via Stellarium/ Eddie Irizzary.
Star chart showing the location of the comet near a couple stars to the left.
Here’s a closer look at the stars Comet Tsuchinshan-ATLAS will be near on the evening of July 11, 2024. Image via Stellarium/ Eddie Irizzary.
Star chart showing a moon at upper left, red hashmarks low at center and Leo to the right.
On the evening of July 13, shortly after sunset, face west and look for the comet in the general direction of the red hashmarks shown here. Image via Stellarium/ Eddie Irizzary.
Star chart showing a fuzzy dot with two brighter, yellow dots to the upper left, and some scattered stars.
Here’s a closer look at the stars Comet Tsuchinshan-ATLAS will be near on the evening of July 13, 2024. Image via Stellarium/ Eddie Irizzary.
Star chart with only stars and lines drawn between for constellations and red hashmarks low to the horizon.
On July 16, 2024, face west shortly after sunset and look for Comet Tsuchinshan-ATLAS in the location indicated by the red hashmarks. Image via Stellarium/ Eddie Irizzary.
A fuzzy glow with a couple stars labeled on either side.
Here’s a closer look at where the comet will lie among the stars on the evening of July 16, 2024. Image via Stellarium/ Eddie Irizzary.

What should we expect?

Comet Tsuchinshan-ATLAS is blazingly speedy. It’s tearing through the inner solar system at 180,610 miles (290,664 km) per hour or 80.74 km per second, relative to Earth. And you can see its amazing speed with a small telescope. You can watch the comet’s location gradually change by comparing its exact position against background stars just 15 minutes later.

As it approaches the interior of the solar system, the celestial visitor from the Oort Cloud should cross the orbit of planet Mars around July 16, 2024. The comet will make its closest approach to the sun (its perihelion) on September 27, 2024.

According to the new study by Sekanina, the comet might disintegrate before reaching perihelion. These predictions are based on the comet’s current performance. But, will it occur?

If it stays intact …

If the comet doesn’t disintegrate, current estimates indicate that around September 27, 2024, it would have a brightness or magnitude between 3 and 4. However, it’ll be very low in the eastern horizon during its closest approach to the sun. Scientists can continue to monitor the comet using instruments like the Solar and Heliospheric Observatory (SOHO), a spacecraft operated by the European Space Agency and NASA.

If still intact after closest approach to the sun, the good news is the high speed of the comet bring it higher in the sky during the following nights after passing by our planet. Thus it will be easier to spot in the western sky.

Its closest approach to Earth comes on October 12, 2024. That is, if it survives. If still intact, current predictions indicate it should have a magnitude between 2 and 3 when closest to our planet. That would make it visible to the unaided eye, although not as bright as previously expected.

Recent images obtained by advanced astrophotographers show a faint but very long secondary tail, an ion tail as long as three lunar diameters!

And if it disintegrates …

However, the appearance of the comet might change soon, if the disintegration process is correct. Sekanina said in his study:

I have assembled extensive circumstantial evidence to support a notion that the comet’s nucleus is currently, and has already been for some time, in the process of progressive fragmentation, which will continue until the point of complete deactivation and disintegration. Given the perihelion distance of 0.39 AU, I expect that the object will disappear and cease to exist as an active comet before perihelion.

The comet has failed to brighten as it approaches the sun. Plus the shape of the dust trail is not looking good for some experts. Sekanina added:

Comet Tsuchinshan-ATLAS exhibits traits that are diagnostic of extensive fragmentation of the nucleus, even though no distinct companion has been observed as of early July.

Discovery and naming

The Asteroid Terrestrial-impact Last Alert System (ATLAS) telescope in South Africa discovered Comet C/2023 A3 on February 22, 2023. Additionally, observers at Purple Mountain (Zijin Shin or Tsuchinshan) Observatory in China found the comet independently on images from January 9, 2023. Therefore, the comet also has the nickname Tsuchinshan-ATLAS.

At discovery, the comet was still 7.3 astronomical units (AU) from the sun, and shining at a dim magnitude 18.

Preliminary analysis of its trajectory suggests comet “A3” completes an orbit around the sun every 80,660 years.

Side by side images with gray background and black dots, with one dot in differint position in the panels.
View at EarthSky Community Photos. | Filipp Romanov captured these images showing movement of the new comet, originally labeled A10SVYR, and now officially C/2023 A3. Filipp took these images confirming the new comet with remote iTelescopes in Chile and Australia on February 24, 2023. Thank you, Filipp!

The path of Comet C/2023 A3

After the comet gets closest to the sun, it will swing around near Earth. But as it does so, it passes almost directly between Earth and the sun, making it challenging to view. In early October, the comet will be in the dawn sky in Leo and near the constellations Hydra and Crater.

Then in late October, as it appears on the other side of the sun, it will move into the evening sky, passing through Serpens Caput and into Ophiuchus.

The turquoise line represents the path of Comet C/2023 A3 into the inner solar system. The comet will be closest to the sun on September 28, 2024, and closest to Earth in October 2024. Image via University of Arizona/ CSS/ D. Rankin.

Finder charts for Comet Tsuchinshan-ATLAS

Star chart showing a comet with tail pointing away from the horizon for 2 dates, 1 closer to the horizon and 1 higher up.
If we are fortunate, the comet will grace our sky from October 14 to 24. Look to the west shortly after sunset for Comet Tsuchinshan–ATLAS. Chart by John Jardine Goss/ EarthSky.
Chart showing partly lit moon high above tick marks showing comet location at lower right.
Comet C/2023 A3 on September 28, 2024 (perihelion). Facing east just before sunrise. Illustration by Eddie Irizarry using Stellarium.
Chart showing dot for Venus near trees and tick marks for comet slightly higher to the right.
Comet C/2023 A3 on October 14, 2024, one day after closest approach to Earth. Facing a western unobstructed horizon just after sunset. Illustration by Eddie Irizarry using Stellarium.
Star chart showing tick marks higher above Venus near the horizon.
Around October 17, 2024, comet C/2023 A3 (Tsuchinshan-ATLAS) might be easier to see in the western sky, as the comet gets higher each subsequent night. Illustration by Eddie Irizarry using Stellarium.

Bottom line: Comet Tsuchinshan-ATLAS, which had a chance to be a bright comet in September and October, may be disintegrating.

Source: Inevitable Endgame of Comet Tsuchinshan-ATLAS (C/2023 A3)

Source link