Succeeded in photography of Comet Tsuchinshan-Atlas at TAO summit facility!

The University of Tokyo Atacama Observatory (TAO) will attempt to photograph Comet Tsuchinshan-Atlas in the early morning hours of September 30 to October 4, 2024 in Chilean time.If we are successful in photography of Comet Tsuchinshan-Atlas, it will be posted on this website.

※As the TAO telescope with a 6.5m diameter aperture is still under construction, the photographs will not be taken using the TAO telescope.

Contents

• What is Comet Tsuchinshan-Atlas (C/2023 A3)?
• Visibility of Comet Tsuchinshan-Atlas
• Photographs of Comet Tsuchinshan-Atlas at the University of Tokyo Atacama Observatory
• • September 30, 2024 (Chilean time)
  • October 1, 2024 (Chilean time)
  • October 2, 2024 (Chilean time)
  • October 3, 2024 (Chilean time)
  • October 4, 2024 (Chilean time)

What is Comet Tsuchinshan-Atlas (C/2023 A3)?

Comet Tsuchinshan-Atlas (C/2023 A3) was first discovered by astronomers at the Tsuchinshan Observatory in China in January 2023 and was redetected by the ATLAS telescope in South Africa in February of that year. This comet, which is thought to have come from the Oort cloud that surrounds our solar system in a spherical shell, is a non-periodic comet with a parabolic orbit and makes only one close approach to the sun. The main body (nucleus) of the comet is formed of ice and rock, and when it approaches the sun, the coma is temporarily covered with gas and the dust and gas ejected from the surface is reflected by the sun's light and observed as a tail. This comet is very large, with a nucleus diameter of about 20 to 40 km.

Visibility of Comet Tsuchinshan-Atlas

Predicting the brightness of a comet is very difficult, and it is not known until it comes close to the sun or the earth. In recent years, comets such as Comet Hyakutake in 1996 and Comet Hale-Bopp the following year were clearly visible to the naked eye. When Comet Tsuchinshan-Atlas was first discovered, it was predicted to reach a maximum brightness of minus 4 to 5 magnitude, however even as they approached the sun (earth) they did not become brighter than expected. It has been pointed out that the sudden brightening in late March and April 2024 may have been caused by the breakup of the comet, and that the volatile components, ice, and dust that form the comet's tail may have evaporated earlier or less frequently than expected. However, ongoing observations suggest that the nucleus is still present, and there is still plenty of promise. The latest prediction is that it will be about 2 to 3 magnitude in late September and 1 to minus magnitude at the time of closest approach to the earth (around October 12). From the Northern Hemisphere, it will be visible in the low eastern sky at dawn from late September to early October, and is expected to be visible in the southwestern sky just after sunset from mid to late October.

Photographs of Comet Tsuchinshan-Atlas at the University of Tokyo Atacama Observatory

The TAO Project was launched in 1998 by project representative Yuzuru Yoshii(Professor emeritus,The University of Tokyo), and is currently constructing a 6.5m telescope at the summit of Cerro Chajnantor in Chile.It is one of the best sites for astronomical observation, not only because of its altitude of 5640m, but also because it is extremely dry and there is almost no city light.We are planning to photograph Comet Tsuchinshan-Atlas from the summit of Cerro Chajnantor. The first image will be taken before dawn on October 1 (Chilean time), and if all goes well, the image will be released on the day. After that, we plan to continue photographing for about a week, and the latest images will be uploaded to this site. Please keep checking this site as we look forward to one of the biggest astronomical phenomena of the year, Comet Tsuchinshan-Atlas.

※As the TAO telescope with a 6.5m diameter aperture is still under construction, the photographs will not be taken using the TAO telescope.

September 30, 2024 (Chilean time)

On September 30, 2024, from 04:48 to 06:30 (Chilean time), the Comet Tsuchinshan-Atlas was successfully photographed at an altitude of 5640 meters on the University of Tokyo Atacama Observatory (TAO) site.

▲Still photograph of Comet C/2023 A3 (06:09, 30, Sept. 2024) The photograph would like to have been taken early in the dark hours, however clouds in the eastern sky meant that we had to take photographs in twilight. Even so, the comet was clearly visible to the naked eye in the twilight. ( Time of the photo: 30 Sep 2024, 6:09AM (CST), Camera: Canon EOS R5, Lens: Canon RF85mmF1.2L USM, Exposure time: 10 sec x 3frames(total: 30 sec), F-number: F1.8, Sensitivity: ISO800) ※The following credit is required for use of the photograph. “Photographed by TAO Project, The University of Tokyo/Akio Nakanishi” Click here to download high-resolution image files.

Assistant Professor Takahashi, who participated in the filming, has provided the following comment.

We astronomers mostly carry out the observations with telescopes and instruments, dealing with quantified data that is invisible to the eye. On the other hand, many of us also enjoy gazing on the (starry) night sky with our own eyes and having fun various astronomical events. Especially, a once-in-a-lifetime astronomical event such as this comet is very exciting. Although the distance to the comet from the earth is almost the same when viewed from the TAO site at 5,640 meters comparing to from the city, it is so wonderful that it gives the illusion such as the comet is very close by. No wonder people in the past were in awe of the comet. Today was the first time in a long time that I was on the summit at night. The starry sky at the summit of Cerro Chajnantor was so wonderful that I felt as if the stars were falling, or as if I was being draws into the dark night sky. This time, a comet was added to such a view, making the starry sky even more fantastic. I was so impressed that my body trembled when a faint ray of light of the comet came into view from the eastern sky. As the sky brightened with the dawn, the comet seemed to melt away and disappear into the sky, becomes impressive astronomical events that will remain deeply etched in my mind. The comet temporarily cannot be seen because it will overlaps in the direction to the sun, but it will become to be seen in the western sky after sunset on and after October 12 (UTC), when it will have passed perigee. I can’t stop looking forward to seeing more exciting appearance of this comet in the future. TAKAHASHI Hidenori Assistant Professor, Kiso Observatory, Institute of Astronomy, Graduate School of Science, The University of Tokyo ▲Comet Tsuchinshan-Atlas, the TAO enclosure, the Milky Way, and the Large Magellanic Cloud. The tail of Comet can be seen extending vertically in the left center of the photo. The TAO enclosure is towering on the right edge of the photo. In the center, the light belt of Milky Way extends from high in the eastern sky to the southeastern horizon. The Large Magellanic Cloud can also be seen between the Milky Way and the enclosure. ( Time of the photo: 30 Sep 2024, 6:07 AM (CST), Camera: Canon EOS M2, Lens: SIGMA 10mm F2.8 EX DC Fisheye HSM, Exposure time: 13 sec, F-number: F2.8, Sensitivity: ISO3200, Color profile: sRGB) ※The following credit is required for use of the photograph. “Photographed by TAO Project, The University of Tokyo/Hidenori Takahashi” Click here to download high-resolution image files.

October 1, 2024 (Chilean time)

On October 1, 2024, from 05:50 to 06:20 (Chilean time), the Comet Tsuchinshan-Atlas was taken the photographed at an altitude of 5640 meters on the University of Tokyo Atacama Observatory (TAO) site.

▲Still photograph of Comet C/2023 A3 (05:55, 1, Oct. 2024) This photo is composed so that the top of the image is in the direction of the north celestial pole according to the basic rules of astrophotography. (Time of the photo: 1 Oct 2024, 5:55AM (CST), Camera: Canon EOS R5, Lens: Canon RF135mmF1.2L USM (Trimmed to the equivalent of a 200mm lens), Exposure time: 20 sec x 3frames(total: 60 sec), F-number: F2.0, Sensitivity: ISO1000) ※The following credit is required for use of the photograph. “Photographed by TAO Project, The University of Tokyo/Akio Nakanishi” Click here to download high-resolution image files.

Assistant Professor Takahashi has provided the following photo.

▲Comet Tsuchinshan-Atlas, the Milky Way, and Zodiacal light In addition to the comet and MW, zodiacal light which extend from near the comet to left-top direction can be seen. Zodiacal light is a faint glow of diffuse light centered on the sun along the ecliptic on the celestial sphere. ( Time of the photo: 1 Oct 2024, 5:47 AM (CST), Camera: Canon EOS M2, Lens: SIGMA 10mm F2.8 EX DC Fisheye HSM, Exposure time: 13 sec, F-number: F2.8, Sensitivity: ISO3200, Color profile: sRGB) ※The following credit is required for use of the photograph. “Photographed by TAO Project, The University of Tokyo/Hidenori Takahashi” Click here to download high-resolution image files.

October 2, 2024 (Chilean time)

On October 2, 2024, from 05:30 to 06:10 (Chilean time), the Comet Tsuchinshan-Atlas was taken the photographed at an altitude of 5640 meters on the University of Tokyo Atacama Observatory (TAO) site.

▲Still photograph of Comet C/2023 A3 (06:06, 2, Oct. 2024) Photo of Comet Tsuchinshan-Atlas together with the enclosure of the TAO 6.5m telescope. To the left of the comet is a silhouette of the monument at the summit of Cerro Chajnantor. The Large Magellanic Cloud is at the upper right of the photo, and the bright star to its left is Canopus of Carina, which is visible only at very low in the sky in Japan. And the Milky Way runs from the top of the enclosure to the upper left. ( Time of the photo: 2 Oct 2024, 6:06 AM (CST), Camera: Canon EOS R5 mark II, Lens: SIGMA 14mm F1.8 DG HSM using Kenko Tokina rear prosofton filter No.050, Exposure time: 15 sec, F-number: F2.5, Sensitivity: ISO1600) ※The following credit is required for use of the photograph. “Photographed by TAO Project, The University of Tokyo/Akio Nakanishi” Click here to download high-resolution image files.

▲Still photograph of Comet C/2023 A3 (05:56, 2, Oct. 2024) (Time of the photo: 2 Oct 2024, 5:56 AM (CST), Camera: Canon EOS R5, Lens: Canon RF50mmF1.2L USM, Exposure time: 10 sec x 4 frames (total: 40 sec), F-number: F2.0, Sensitivity: ISO1600) ※The following credit is required for use of the photograph. “Photographed by TAO Project, The University of Tokyo/Akio Nakanishi” Click here to download high-resolution image files.

Assistant Professor Takahashi has provided the following photo.

Because I was scheduled to return to Japan temporarily today, I attempted to take a photograph the comet from San Pedro de Atacama, where the TAO base facility is located. I was able to see the comet with the naked eye from the TAO base facility, but I felt that the comet seen from the summit was clearer and had a more three-dimensional effect. The beautiful gradation of colors from the deep blue of the night sky to the red of the twilight can be better seen from the summit at 5,640 meters. I look forward to seeing the comet at sunset past the perigee point on my next summit visit. TAKAHASHI Hidenori Assistant Professor, Kiso Observatory, Institute of Astronomy, Graduate School of Science, The University of Tokyo ▲The Comet Tsuchinshan-Atlas taken from TAO base facility at San Pedro de Atacama The lights of the TAO summit facility can be seen at the mountain peak to the lower right of the comet. In the lower left corner, the red taillights of a convoy of work vehicles to the summit can be seen. Daily work begins early in the morning at TAO, because the wind tends to pick up in the afternoon near the summit. (Time of the photo: 2 Oct 2024, 6:14 AM (CST), Camera: Canon EOS M2, Lens: Canon EF-M 53mm, Exposure time: 13 sec, F-number: F5.6, Sensitivity: ISO1600, Color profile: sRGB) ※The following credit is required for use of the photograph. “Photographed by TAO Project, The University of Tokyo/Hidenori Takahashi” Click here to download high-resolution image files.

October 3, 2024 (Chilean time)

On October 3, 2024, from 4:56 to 6:25 (Chilean time), the Comet Tsuchinshan-Atlas was taken the photographed at an altitude of 5640 meters on the University of Tokyo Atacama Observatory (TAO) site.

▲Still photograph of Comet C/2023 A3 (5:53, 3, Oct. 2024) The composition is vertical, and the comet's tail is almost completely in the longitudinal direction of the 85mm lens. The field of view in the longitudinal direction of the 85mm lens is 24°, so the comet's tail extends to be about 20° or more. There were no clouds at low sky on this day, then the nucleus of the comet can be taken which was rising from the horizon. The comet was clearly observable even at very low sky, which is a great advantage of astronomical observation at high altitudes. (Time of the photo: 3 Oct 2024, 5:53AM (CST), Camera:Canon EOS R5 , Lens:Canon RF 85mmF1.2L USM , Exposure time: 15 sec x 4frames (total: 60 sec), F-number: F1.8, Sensitivity: ISO1000) ※The following credit is required for use of the photograph. “Photographed by TAO Project, The University of Tokyo/Akio Nakanishi” Click here to download high-resolution image files.

October 4, 2024 (Chilean time)

On October 4, 2024, from 5:10 to 6:15 (Chilean time), the Comet Tsuchinshan-Atlas was taken the photographed at an altitude of 5640 meters on the University of Tokyo Atacama Observatory (TAO) site.

▲Still photograph of Comet C/2023 A3 (6:00, 4, Oct. 2024) On this day, there were many clouds in the eastern sky and photographs were taken through the clouds. Since the comet was gradually approaching to the sun, the photographing time was limited. The Milky Way can be seen in the upper left direction from slightly above the center of the right edge. The bright star in the upper left corner is Procyon in the constellation Canis Minor, and Regulus in the constellation Leo can be seen below it. (Time of the photo: 4 Oct 2024, 6:00AM (CST), Camera:FUJIFILM GFX100Ⅱ, Lens:FUJIFILM GF20-35mmF4 R WR(used at 20mm), Exposure time: 40 sec, F-number: F5.0, Sensitivity: ISO3200) ※The following credit is required for use of the photograph. “Photographed by TAO Project, The University of Tokyo/Akio Nakanishi” Click here to download high-resolution image files.

Summarizing photographing the comet at the summit of Cerro Chajnantor

Finally, the following are comments by astrophotographer Akio Nakanishi after five days of photographing comets.

“Summarizing photographing the comet at the summit of Cerro Chajnantor” I have just finished five days of photographing Comet Tsuchinshan-Atlas at the summit of Chajnantor. There were two major accomplishments for me during this taking the photographs. First, I was able to take excellent photographs of the comet at the summit of Chajnantor, the best location in the world. In spite of Comet Tsuchinshan-Atlas had shown promise of becoming a large comet since its discovery, it was in danger of disintegrating due to a slow increase in brightness at one time. However, it turned out to be a great comet with the brightness of 1 magnitude or more and a tail length of more than 20 degrees. As large comets are thought to come along only once every few years to a few decades generally, I feel as if Comet Tsuchinshan-Atlas came from far away in the solar system to congratulate TAO on its just completion. Second, I was able to visit the summit of Cerro Chajnantor for the first time in exactly ten years to photograph this comet. Ten years ago we were still in the time of the miniTAO 1.0m telescope, so it was very emotional to see that the observatory and the roads were like a different place compared to then. If possible, I would definitely like to visit again the next time when the TAO 6.5m telescope is ready for its first light. Only me and Dr. Takahashi are listed as the photographers for this caravan, however it would not have been possible without the actual cooperation and support of many related people involved with TAO. In closing, I would like to express my gratitude and deep appreciation to all for making this photographic caravan. Akio Nakanishi, Astrophotographer ※The following credit is required for use of the photograph. “Photographed by TAO Project, The University of Tokyo”

In this segment, photos taken by the photography team in San Pedro de Atacama, where the TAO base facility is located, are presented.

▲Still photograph of solar eclipes(17:20, 2, Oct. 2024) An annular eclipse occurred in the southern part of Chile and on Easter Island today. San Pedro de Atacama, where the TAO base facility is located, is far from the annular eclipse zone, so it was not possible to see the annular eclipse, but a partial solar eclipse could be seen. This photograph was taken with a special filter for solar photography with an exposure factor of 100,000. The photo was taken in a horizontal composition on a photographic tripod, so the upper part of the photo is in the zenith direction. The activity of the sun is currently very high, and many sunspots can be seen on the surface of the sun in this photo. (Time of the photo: 2 Oct 2024, 17:20 AM (CST), Camera: FUJIFILM GFX100Ⅱ, Lens: FUJIFILM GF250mmF4 R LM OIS WR, Exposure time: 1/500 sec, F-number: F5.6, Sensitivity: ISO100) ※The following credit is required for use of the photograph. “Photographed by TAO Project, The University of Tokyo/Akio Nakanishi” Click here to download high-resolution image files.