N. James (July 6, 2020). "Visual observations page". Comet Section. British Astronomical Association. Archived from the original on July 16, 2020. Retrieved July 13, 2020.
cobs.si
"C/2020 F3 (NEOWISE)". Comet Observation database (COBS). Archived from the original on July 16, 2020. Retrieved July 18, 2020.
JPL Horizons barycentric solution for epoch 1800 (before entering planetary region)
Goto JPL Horizons
1800-Jan-01 is "PR = 1.64 × 106/365.25 days" = 4490 years
2200-Jan-01 is "PR = 2.48 × 106/365.25 days" = 6789 years
(For long-period comets on multi-thousand year orbits, asymmetric outgassing will affect the highly sensitive orbital period and eccentricity.)
"Horizons Web-Interface". ssd.jpl.nasa.gov. Archived from the original on July 8, 2020. Retrieved July 24, 2020. Ephemeris Type: Observer, Observer Location: Geocentric 500, Note: Closest approach occurs when deldot flips from negative to positive; Maximum northern declination is 2020-Jul-18 07h)
A. MacRobert (April 2, 2013). "Updates on Comet PanSTARRS". Sky & Telescope. Archived from the original on November 12, 2020. Retrieved November 11, 2020.
S. Yoshida. "C/2020 F3 (NEOWISE)". www.aerith.net. Archived from the original on May 14, 2020. Retrieved April 4, 2020.
"C/2020 F3 (NEOWISE)". Comet Observation database (COBS). Archived from the original on July 16, 2020. Retrieved July 18, 2020.
"Horizons Web-Interface". ssd.jpl.nasa.gov. Archived from the original on July 8, 2020. Retrieved July 24, 2020. Ephemeris Type: Observer, Observer Location: Geocentric 500, Note: Closest approach occurs when deldot flips from negative to positive; Maximum northern declination is 2020-Jul-18 07h)
A. MacRobert (April 2, 2013). "Updates on Comet PanSTARRS". Sky & Telescope. Archived from the original on November 12, 2020. Retrieved November 11, 2020.
N. James (July 6, 2020). "Visual observations page". Comet Section. British Astronomical Association. Archived from the original on July 16, 2020. Retrieved July 13, 2020.