C/1961 R1 (Humason)

Not to be confused with another long-period comet with the same name: C/1960 M1 (Humason).

C/1961 R1 (Humason)

Comet Humason photographed from the Palomar Observatory on 4 September 1962
Discovery
Discovered by	Milton L. Humason
Discovery date	1 September 1961
Designations
Alternative designations	1961e 1962 VIII
Orbital characteristics [1]
Epoch	12 May 1963 (JD 2438161.5)
Observation arc	1,517 days (4.15 years)
Number of observations	80
Aphelion	408.71 AU
Perihelion	2.133 AU
Semi-major axis	205.42 AU
Eccentricity	0.98961
Orbital period	2,883 years (inbound) 2,516 years (outbound)
Inclination	153.278°
Longitude of ascending node	155.439°
Argument of periapsis	233.562°
Last perihelion	10 December 1962
TJupiter	–1.588
Earth MOID	1.2247 AU
Jupiter MOID	1.0725 AU
Physical characteristics [2] [3]
Dimensions	30–41 km (19–25 mi)
Comet total magnitude (M1)	1.35–3.5
Comet nuclear magnitude (M2)	10.1

Comet Humason, formally designated C/1961 R1 (a.k.a. 1962 VIII and 1961e), was a non-periodic comet discovered by Milton L. Humason on 1 September 1961. Its perihelion was well beyond the orbit of Mars, at 2.133 AU. The outbound orbital period is about 2,516 years.

Physical properties

It was a "giant" comet, much more active than a normal comet for its distance to the Sun, with an absolute magnitude of 1.35−3.5, ^[3] and a nucleus diameter estimated at 30–40 km (19–25 mi). ^[2] It could have been up to a hundred times brighter than an average new comet. It had an unusually disrupted or "turbulent" appearance. ^[4] It was also unusual in that the spectrum of its tail showed a strong predominance of the ion CO ⁺, a result previously seen unambiguously only in C/1908 R1 (Morehouse). ^[5]

See also

• C/1729 P1 (Sarabat)
• C/1995 O1 (Hale–Bopp)
• C/2014 UN₂₇₁ (Bernardinelli–Bernstein)

References

1. "C/1961 R1 – JPL Small-Body Database Lookup". ssd.jpl.nasa.gov. Jet Propulsion Laboratory . Retrieved 29 May 2019.
2. "Comets: Comet Humason 1961e". Irish Astronomical Journal . 6: 191. 1964. Bibcode:1964IrAJ....6Q.191.
3. M. R. Kidger (3 April 1997). "Comet Hale–Bopp Light Curve". jpl.nasa.gov. NASA / JPL. Archived from the original on 7 April 2023. Retrieved 10 January 2025.
4. J. C. Brandt; R. D. Chapman (2004). Introduction to Comets. Cambridge University Press. p. 156. ISBN   978-0-521-00466-4.
5. W. F. Huebner (1990). Physics and Chemistry of Comets. Springer-Verlag. p. 246. ISBN   978-0-387-51228-0. ISSN   0941-7834.

External links

• C/1961 R1 at the JPL Small-Body Database
  • Close approach  · Discovery  · Ephemeris  · Orbit viewer  · Orbit parameters  · Physical parameters