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Comet Nishimura and the Sigma-Hydrid meteors

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Kelly Kizer Whitt

and

Eddie Irizarry

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December 9, 2023

Check out these Comet Nishimura photos from around the world.

Nishimura and the Sigma-Hydrid meteors

Comet C/2023 P1 (Nishimura) burst into our consciousness in August of 2023. It never got as bright as some hoped, but it still made a glorious target for astrophotographers. Astronomers think Nishimura may be the parent comet of an annual meteor shower known as the Sigma-Hydrids. This minor annual shower is active each year between December 9 and 12.

The video below is from December 2022, taken in the Caribbean. It’s a Sigma-Hydrid meteor, a possible Nishimura-related meteor!

Videos of Nishimura

Professional observatories that peer at the sun have caught the comet in their images. You’ll find some amazing videos of the comet below.

Comet Nishimura – that great icy ball moving through space, which so many have captured on film – was closest to Earth on September 12. It was then closest to the sun (perihelion) on September 17.

Meanwhile, the comet is also expected to reappear in our dawn skies toward the end of 2023. But by then it’ll be too distant, and too dim, to view, as it sweeps farther away.

Wondering what happened to comet Nishimura? It's still quite happily sunbathing in the field of view of our @USNRL HI-1 camera on @NASA STEREO-A! Lots of great ion tail / solar wind interaction happening! ????

Download the full-res movie here: https://t.co/gkv2HCpIUS pic.twitter.com/xzHvdgBfjt

— Karl Battams (@SungrazerComets) September 26, 2023

The story of comet Nishimura

Hideo Nishimura of Kakegawa, Japan, was photographing the night sky on August 11 and 12, 2023, when he captured a new comet that now bears his name: comet C/2023 P1 (Nishimura). In fact, the comet was hiding in the sun’s glare before Nishimura picked it up in his images.

It continued to brighten as it closed in on the sun (perihelion was September 17). Later, after passing closest to Earth on September 12, it emerged low in the evening sky. Some saw it with binoculars in the western evening twilight.

Nishimura: Blue trail on the left and bright planet on the right in early morning twilight. City lights below. — View at EarthSky Community Photos. | Petr Horalek in Zahradne, Slovakia, made this composite image of new comet Nishimura (left) and Venus, the brightest planet, on September 9, 2023, when the comet was in the morning sky. Thank you, Petr! Now, the comet has moved to the evening sky, and early sightings suggest it has brightened.

A local comet

On September 1, 2023, NASA/ JPL made new orbital calculations that indicated that comet Nishimura orbits the sun every 435 years, which suggests this is a “local comet” from our solar system and not an interstellar comet.

Closest approach to Earth occurred on September 12, 2023, when the comet passed 78 million miles (125 million km) from Earth.

Perihelion – or closest approach to the sun – was on September 17, 2023, at 27 million miles (43 million km) from our star.

In fact, during perihelion, comet Nishimura passed closer to the sun than Mercury’s orbit.

Complex diagram of grid with sun at center and circle for Earth's orbit, and curving path of the comet. — Path of new comet C/2023 P1 (Nishimura) around the sun. In this chart from Guy Ottewell, the grid lines are 1 AU (1 Earth-sun distance) apart. Stalks on the comet’s path mark 1-month intervals. Red lines connect the comet and Earth, and the comet and the sun, at their closest. Does the path of the comet through space match that of the Sigma-Hydrid meteor shower? Image via Guy Ottewell. Used with permission.

Sky chart showing boundaries of constellations and a black line arcing through, which is the comet's path. — View larger. | Here’s the path of comet Nishimura, largely through the zodiacal constellations. The comet climbed into the sky’s Northern Hemisphere on March 28. It was in conjunction with the sun (behind the sun) on June 15. Then, it ascended northward through the ecliptic plane on August 22. It was farthest north (declination about 24 degrees) on September 4. Image via Guy Ottewell. Used with permission.

Sightings of comet Nishimura

Comet Nishimura (C/2023 P1) on Sept 5, 2023. For this single shot I used my A7s and a 135mm lens.

Nishimura is a new comet that was discovered on August 11, 2023. It's expected to brighten to a magnitude of 1.8. Its closest approach to us will be on Sep 12 and its perihelion on… pic.twitter.com/BXhDo0IOpq

— Dr. Sebastian Voltmer (@SeVoSpace) September 6, 2023

comet C/2023 P1 (Nishimura) from Belfast, N Ireland at around 5am on 4th Sept 2023. Cropped from a 100mm image – stack of 50 x 3secs at ISO800. (Some problems with stacking caused a halo above neighbour's roof!) @martinastro2005 pic.twitter.com/jCuuZa3egN

— Philip?EcotrakNI (@EcotrakNI) September 4, 2023

comet C/2023 P1 (Nishimura): Such a strong solar wind. The disconnection event on September 2nd – the spectacular development in a 20-minute animation (RASA 11 QHY600) and 4x80sec red Michael Jäger pic.twitter.com/qf43YqhBbl

— Michael Jäger (@Komet123Jager) September 2, 2023

Bottom line: Comet Nishimura may be the parent comet to the Signma-Hydrid meteor shower, which peaks between December 9 and 12.

See photos of comet Nishimura from the EarthSky community

Via:

NASA

Harvard

IAU Minor Planet Center

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December 9, 2023

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Kelly Kizer Whitt

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About the Author:

Kelly Kizer Whitt has been a science writer specializing in astronomy for more than two decades. She began her career at Astronomy Magazine, and she has made regular contributions to AstronomyToday and the Sierra Club, among other outlets. Her children’s picture book, Solar System Forecast, was published in 2012. She has also written a young adult dystopian novel titled A Different Sky. When she is not reading or writing about astronomy and staring up at the stars, she enjoys traveling to the national parks, creating crossword puzzles, running, tennis, and paddleboarding. Kelly lives in Wisconsin.

Eddie Irizarry

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About the Author:

Eddie Irizarry of the Sociedad de Astronomía del Caribe (Astronomical Society of the Caribbean) has been a NASA Solar System Ambassador since 2004. He loves public outreach and has published multiple astronomy articles for EarthSky, as well as for newspapers in Puerto Rico. He has also offered dozens of conferences related to asteroids and comets at the Arecibo Observatory. Asteroid 33012EddieIrizarry, a 7.8 km space rock, has been named in his honor.