C / 2019 Y4 (ATLAS)

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C / 2019 Y4 (ATLAS) [i]
C / 2019 Y4 (ATLAS) on March 19, 2020
C / 2019 Y4 (ATLAS) on March 19, 2020
Properties of the orbit ( animation )
Epoch:  March 7th 2020 ( JD 2,458,915.5)
Orbit type long-period
Numerical eccentricity 0.99924
Perihelion 0.253 AU
Aphelion 661.0 AU
Major semi-axis 330.6 AU
Sidereal period ~ 6011 a
Inclination of the orbit plane 45.4 °
Perihelion May 31, 2020
Orbital velocity in the perihelion 83.7 km / s
history
Explorer Asteroid Terrestrial-Impact Last Alert System
Date of discovery December 28, 2019
Source: Unless otherwise stated, the data comes from JPL Small-Body Database Browser . Please also note the note on comet articles .

C / 2019 Y4 (ATLAS) was a comet that promised to become a noticeable object in the night sky in 2020 . However, it broke beforehand and could no longer be freely observed.

Discovery and observation

The comet was discovered on December 28, 2019 by the asteroid Terrestrial-impact Last Alert System in the constellation Great Bear . When it was discovered, the comet had a magnitude of 19.6 mag. In mid-March 2020, the brightness increased to 9 mag. At the end of March the comet reached a brightness of 7.5 mag, but in the next few days the brightness dropped rapidly to around 8.5 mag.

In April 2020, the comet's core was observed to have broken into more than 20 pieces that were moving apart. The five largest of these were given the designations C / 2019 Y4 – A to –E and were observed for a few days to weeks.

The fragments of C / 2019 Y4 (ATLAS) on April 20 and 23, 2020

Scientific evaluation

The orbital elements of C / 2019 Y4 (ATLAS) and those of the Great Comet C / 1844 Y1 are very similar in all parameters. It is therefore believed that both comets are fragments of a larger comet that broke when it last passed the Sun about 5,000 years ago .

Orbit

An elongated elliptical orbit could be determined for the comet from 1250 observation data over a period of 115 days , which is inclined by around 45 ° to the ecliptic . The comet's orbit thus runs at an angle to the planets of the planets and it ran through its orbit in the same way as these. Had he not gone in April, he would have the point nearest the Sun ( perihelion through) on 31 May 2020 he would be about million 37.8 km have been removed from the sun and would have been within the orbit of the area Mercury found . On May 22nd it would have passed Venus in about 75.9 million km and on May 23 it would have reached the closest approach to Earth with about 0.78 AU / 116.8 million km .

The comet moved in an extremely elongated elliptical orbit around the sun. According to the orbital elements afflicted with a certain uncertainty and taking into account non-gravitational forces , long before its passage through the inner solar system in 2020 , its orbit still had an eccentricity of around 0.99914 and a semi-major axis of around 293 AU, so that its orbit period was about 5000 years. The last passage through the inner solar system could therefore have taken place around the year –2980 (uncertainty ± 34 a). Before the comet reached the inner solar system, it passed Jupiter on April 16, 2016 at a distance of about 10 ¾ AU.

Web links

Individual evidence

  1. ↑ A. Ashford: Get ready for Comet ATLAS (C / 2019 Y4) in the northern spring sky! In: Seti Institute. Pole Star Publications Limited, April 3, 2020, accessed July 12, 2020 .
  2. ^ F. Marchis: Comet Atlas: A comet for all of us? In: SETI Institute. SETI Institute, April 2, 2020, accessed on July 12, 2020 .
  3. ↑ DWE Green: CBET 4712: COMET C / 2019 Y4. Central Bureau for Astronomical Telegrams, January 11, 2020, accessed July 12, 2020 .
  4. ↑ M. Risch: Comet ATLAS (C / 2019 Y4) surprised. In: Baader Planetarium. Baader Planetarium GmbH, March 12, 2020, accessed on July 12, 2020 .
  5. ↑ G. van Buitenen: C / 2019 Y4 (ATLAS) - DISINTEGRATED. In: astro.vanbuitenen.nl. Retrieved July 12, 2020 .
  6. ↑ S. Yoshida: C / 2019 Y4 (ATLAS). In: Seiichi Yoshida's Home Page. July 7, 2020, accessed on July 12, 2020 .
  7. ↑ T. Banner: Comets "Swan" and "Neowise": Will they soon be visible to the naked eye? In: Frankfurter Rundschau. Frankfurter Rundschau, May 20, 2020, accessed on April 30, 2020 .
  8. ↑ Quanzhi Ye, Man-To Hui: Continuing Fragmentation of C / 2019 Y4 (ATLAS). In: The Astronomer's Telegram. April 21, 2020, accessed on April 23, 2020 .
  9. ↑ B. King: Oh No! Comet ATLAS Is Fragmenting. In: Sky & Telescope. AAS Sky Publishing LLC., April 7, 2020, accessed July 12, 2020 .
  10. ↑ C / 2019 Y4 (ATLAS) in the Small-Body Database of the Jet Propulsion Laboratory (English).Template: JPL Small-Body Database Browser / Maintenance / Alt
  11. ↑ SOLEX 12.1 by A. Vitagliano. Retrieved July 9, 2020 .