Comet NEOWISE according to Wikipedia

C/2020 F3 (NEOWISE)

From Wikipedia, the free encyclopedia

Jump to navigationJump to search

Take a short survey and help us improve Wikipedia

C/2020 F3 (NEOWISE)
2020-07-13 02-3x-xx-smx 30x30s 300mm f4 2048px.jpg

C/2020 F3 (NEOWISE) photographed from France on July 13, 2020
Discovered by NEOWISE
Discovery date March 27, 2020[1]
Orbital characteristics A
Epoch 2458953.5 (April 14, 2020)
Observation arc 70 days
Number of
Orbit type Long period comet
Aphelion 544 AU (inbound)
720 AU (outbound)
Perihelion 0.29478 AU
Semi-major axis 272 AU (inbound)
360 AU (outbound)
Eccentricity 0.99921
Orbital period ~4500 yrs (inbound)[2]
~6800 yrs (outbound)
Inclination 128.93°
Node 61.01°
Argument of
TJupiter -0.408
Earth MOID 0.36 AU (54 million km; 140 LD)
Jupiter MOID 0.81 AU (121 million km)
Dimensions ~5 km[1]
Last perihelion July 3, 2020

C/2020 F3 (NEOWISE), or Comet NEOWISE, is a retrograde comet with a near-parabolic orbit discovered on March 27, 2020, by astronomers using the NEOWISE space telescope. At that time it was a 10th magnitude comet, located 2 AU (300 million km; 190 million mi) away from the Sun and 1.7 AU (250 million km; 160 million mi) away from Earth.[3]

By July 2020 it was bright enough to be visible to the naked eye. For observers in the northern hemisphere, in the morning the comet appears low on the northern-eastern horizon, below Capella. In the evening it can be seen in the north-western sky. In the second half of July 2020 it will appear to pass through the constellation of Ursa Major, below the asterism of The Plough (Big Dipper).

The comet is notable for being one of the brightest visible to observers in the northern hemisphere since Comet Hale–Bopp in 1997.[4] Under dark skies it can be clearly seen with the naked eye[5] and is expected to remain visible to the naked eye throughout most of July 2020.[3]

History and observations[edit]

Diagram of the comet’s nearly parabolic orbit

File:NEOWISE from the International space station.webm

Video rendering of the images captured by the International Space Station from its orbit on July 5, 2020, showing NEOWISE rising up against Earth

The object was discovered by a team using the NEOWISE space telescope on March 27, 2020.[1] It was classified as a comet on March 31 and named after NEOWISE on April 1.[6] It has the systematic designation C/2020 F3, indicating a non-periodic comet which was the third discovered in the second half of March 2020.

Comet NEOWISE made its closest approach to the Sun (perihelion) on July 3, 2020, at a distance of 0.29 AU (43 million km; 27 million mi). This passage increases the comet’s orbital period from about 4500 years to about 6800 years.[2] Its closest approach to Earth will occur on July 23, 2020, 01:14 UT, at a distance of 0.69 AU (103 million km; 64 million mi) while located in the constellation of Ursa Major.[7]

Seen from Earth, the comet was less than 20 degrees from the Sun between June 11 and July 9, 2020. By June 10, 2020, as the comet was being lost to the glare of the Sun, it was apparent magnitude 7.[8] When the comet entered the field of view of the SOHO spacecraft’s LASCO C3 instrument on June 22, 2020, the comet had brightened to about magnitude 3.[8] By early July, Comet NEOWISE had brightened to magnitude −1,[9][10] far exceeding the brightness attained by C/2020 F8 (SWAN), and had developed a second tail. The first tail’s color is magenta and made of gas and ions; the second twin tail is a golden color and made of dust, like the tail of Comet Hale-Bopp, this combination resembles comet C/2011 L4(PANSTARRS). The comet is brighter than C/2011 L4 (PANSTARRS), but not as bright as Hale–Bopp was in 1997. According to the British Astronomical Association, the comet brightened from a magnitude of about 8 at the beginning of June to -2 in early July.[11] This would make it brighter than Hale Bopp. However, as it was very near to the Sun, it was reported as 0 or +1 magnitude and remained that bright for only a few days. After perihelion, the comet began to fade at about the same rate as it had previously brightened.

From the infrared signature Joseph Masiero estimates the diameter of the comet nucleus to be approximately 5 km (3 mi).[1] The nucleus is similar in size to many short-period comets such as 2P/Encke7P/Pons-Winnecke8P/Tuttle14P/Wolf, and 19P/Borrelly.[12] By July 5 NASA’s Parker Solar Probe had captured an image of the comet, from which astronomers also estimated the diameter of the comet nucleus at approximately 5 km.[13]


Comet position in the sky – the retrograde loops are caused by parallax from Earth’s annual motion around the Sun; the most movement occurs when the comet is closest to Earth



  1. Jump up to:a b c d Mace, Mikayla (July 8, 2020). “Comet NEOWISE Sizzles as It Slides by the Sun, Providing a Treat for Observers”Infrared Processing and Analysis Center. Retrieved July 13, 2020.
  2. Jump up to:a b JPL Horizons barycentric solution for epoch 1950 (before entering planetary region)
    Goto JPL Horizons
    Ephemeris Type: Orbital Elements
    Center: @0 (Solar System Barycenter)
    Time Span: 1950-01-01 to 2050-01-01 and Step Size: 100 years
    1950-Jan-01 is “PR= 1.63E+06 / 365.25 days” = 4462 years
    (For long period comets on multi-thousand year orbits, asymmetric outgassing will affect the highly sensitive orbital period and eccentricity.)
  3. Jump up to:a b Seiichi Yoshida. “C/2020 F3 ( NEOWISE )”. Retrieved April 4, 2020.
  4. ^ Siegel, Ethan. “How To See Comet NEOWISE, Earth’s Most Spectacular Comet Since 2007”Forbes. Retrieved July 13,2020.
  5. ^ “How to see Comet NEOWISE”. EarthSky. Retrieved July 11,2020.
  6. ^ “COMET C/2020 F3 (NEOWISE)”Minor Planet Electronic Circulars. 2020-G05. April 1, 2020. Retrieved July 13, 2020On behalf of NEOWISE (C51), J. Masiero reported on March 31 UT that this object showed clear signs of cometary activity.
  7. ^ JPL Horizons closest approach to Earth
    Goto JPL Horizons
    Ephemeris Type: Observer
    Observer Location: 500 (Geocentric)
    (Closest approach occurs when deldot flips from negative to positive)
  8. Jump up to:a b “Comet Observation database (COBS)”. Retrieved May 27,2020. “C/2020 F3 (NEOWISE) plot”
  9. ^ “Comet F3 NEOWISE May Perform in July”. Universe Today. Retrieved June 30, 2020.
  10. ^ “ATel #13853: Morphology and Photometry of Comet C/2020 F3 (NEOWISE) from SOHO”. Astronomer’s Telegram. July 2, 2020.
  11. ^ Nick James (July 6, 2020), “Visual observations page”Comet Section, British Astronomical Association
  12. ^ “JPL Small-Body Database Search Engine: numbered comets and diameter > 4 (km) and diameter < 6 (km)”. JPL Solar System Dynamics. Retrieved July 13, 2020.
  13. ^ Miloslav Druckmuller; Robert Nemiroff; Jerry Bonnell (July 11, 2020), The Tails of Comet NEOWISE, NASA

External links[edit]


This entry was posted in Uncategorized. Bookmark the permalink.