C/1962 C1 (Seki–Lines)
Great Comet of 1962, discovered independently by two observers.
C/1962 C1 (Seki–Lines), also called Comet Seki–Lines or 1962c, was a hyperbolic comet. Richard D. Lines and Tsutomu Seki each spotted it independently on 4 February 1962. It grew very bright in April 1962, after reaching perihelion on 1 April at 0.031 AU (about 4.6 million km), and became known as the Great Comet of 1962.
At discovery, the comet was near ζ Puppis. Two days later, the Lowell Observatory estimated its apparent magnitude at 8. By late February and early March, it was visible to the naked eye as it moved through Eridanus and Cetus. It brightened quickly, and by 27 March its magnitude was estimated between 0 and -1. It reached perihelion on 1 April at roughly 4 million km from the Sun; though it should have been bright enough, no one reported seeing it in daylight. After perihelion, it appeared in the northwestern evening twilight on 3 April with an estimated magnitude of -2.5. Its slightly curved tail measured 10 to 15 degrees in length, showed small striae in photographs, and appeared split in two. The comet faded rapidly through April as its distance from both the Sun and Earth increased, and it could no longer be observed by month’s end. In late May it stayed low, moving in conjunction with the Sun. It was last photographed on 30 May, low in twilight, with a tail 2.5 arcminutes long. The Flagstaff observatory rephotographed it on 27 and 28 October 1962 and again on 27 November 1962. The final observation came on 25 January 1963; photographic attempts in February failed to find it.
Before perihelion, the comet’s spectrum resembled that of Comet Mrkos, with similar intensities of diatomic carbon and NH2. It also showed [O I] and the sodium D-line, which displayed spatial asymmetry.
Quick Facts
- Discovery Ref
- IAUC_1790
- Discoverer
- Tsutomu Seki / Richard D. Lines
- Discovery Date
- 4 February 1962
- Designations
- 1962cICQ1 / 1962 III
- Orbit Ref
- jpl
- Epoch
- 30 May 1962 (JD 2437814.5)
- Observation Arc
- 349 days
- Obs
- 32
- Perihelion
- 0.031 AU
- Eccentricity
- 1.0000045
- Inclination
- 65.01°
- Asc Node
- 304.68°
Facts from the source article.
Lore & Background
The comet was discovered independently by Richard D. Lines and Tsutomu Seki on 4 February 1962, when it was located near ζ Puppis. Two days later, the Lowell Observatory estimated its apparent magnitude at 8. By late February and early March, the comet became visible to the naked eye as it crossed the constellations Eridanus and Cetus. It brightened rapidly, and by 27 March its magnitude was estimated to be 0 to -1. The comet reached perihelion on 1 April 1962 at a distance of about 4 million km (0.027 AU) from the Sun; although it should have been bright enough, no daylight observations were reported.
After perihelion, the comet became visible in the northwestern evening twilight on 3 April, with an estimated magnitude of -2.5. It displayed a slightly curved tail reported to be 10 to 15 degrees long, featuring small striae in photographs, and the tail appeared split in two. The comet faded rapidly during April as its distance from both the Sun and Earth increased, and it could no longer be observed by the end of the month. In late May, the comet remained low as it moved in conjunction with the Sun. It was last photographed on 30 May, with its tail measured at 2.5 arcminutes in length.
The comet was reobserved photographically on 27 and 28 October 1962 and on 27 November 1962 by the Flagstaff observatory. It was last observed on 25 January 1963; photographic attempts in February failed to locate the comet.
Reader's Guide
C/1962 C1 (Seki–Lines) is notable as the Great Comet of 1962, reaching a peak magnitude of -2.5 after perihelion. Its discovery by two independent observers on the same day highlights the collaborative nature of amateur astronomy. The comet's rapid brightening from magnitude 8 in early February to naked-eye visibility by late February, and then to magnitude 0 to -1 by 27 March, demonstrates its dramatic evolution. The perihelion distance of 0.031 AU placed it extremely close to the Sun, yet no daylight observations were reported. The comet's tail, which reached 10 to 15 degrees in length and appeared split, provided a striking visual display. Its spectrum before perihelion was similar to that of comet Mrkos, with notable features including the sodium D-line showing spatial asymmetry. The comet was observed over nearly a year, from February 1962 to January 1963, with a final photographic recovery in late 1962 by the Flagstaff observatory. Its legacy lies in being a well-observed bright comet that contributed to understanding cometary spectra and tail structure.
Did You Know?
- Its perihelion distance was 0.031 AU, about 4.6 million km from the Sun.
- The comet's tail appeared split in two and featured small striae in photographs.
- It was last observed on 25 January 1963, with photographic attempts in February failing to locate it.
Frequently Asked Questions
Who discovered C/1962 C1 (Seki–Lines)?
The comet was found independently on 4 February 1962 by Richard D. Lines and Japanese amateur astronomer Tsutomu Seki, who each spotted it without knowing the other had already logged it. Because both names are attached, it is commonly called the Seki–Lines comet.
What kind of object is C/1962 C1 (Seki–Lines)?
It is a hyperbolic (non-periodic) comet, meaning its trajectory around the Sun is open-ended and it will never return. It made its single perihelion passage on 1 April 1962 at just 0.031 AU, roughly 4.6 million kilometres from the Sun.
How bright did the Great Comet of 1962 actually get?
C/1962 C1 peaked at an apparent magnitude of about −2.5 in late March to early April 1962, making it easily visible to the naked eye and even casting faint shadows on a moonless night. At discovery it had been a modest 8th-magnitude object near ζ Puppis, so the brightening was dramatic over just a few weeks.
Why is C/1962 C1 (Seki–Lines) important to amateur astronomy?
It is a classic example of two independent discoveries by non-professional observers, highlighting how skilled backyard astronomers can make genuine contributions to celestial mechanics. The comet's rapid brightening from magnitude 8 to −2.5 in under a month also made it a favourite case study in how cometary activity can escalate near perihelion.
When was C/1962 C1 (Seki–Lines) last observed and what happened to it afterward?
The comet was last tracked on 25 January 1963 as it faded and receded into the outer solar system. Because its orbit is hyperbolic, it exited the inner solar system on a one-way trajectory and is not expected to reappear.
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