Lick Object of 1921

Last updated
X/1921 P1 (Lick)
Discovery [1]
Discovered by William W. Campbell
Discovery site Lick Observatory
Discovery date7 August 1921
Orbital characteristics [2]
Observation arc 1 day
Perihelion ~0.25 AU
Physical characteristics [3]
–2.0
(1921 apparition)

The Lick Object of 1921 is an unidentified astronomical object that was observed from the Lick Observatory in August 1921. Although follow-up observations were not successfully conducted, it is hypothesized that this object is highly likely a non-periodic comet. [2]

Contents

Observational history

William Wallace Campbell reported the sighting of a star-like object about three degrees from the Sun on the evening of 7 August 1921. [4] [1] Observers noted that the object was as bright as Venus, reaching an apparent magnitude of –2 at its maximum. [3] A possibility that it was a nova explosion was ruled out due to its high relative position (about 40 degrees) to the Galactic plane. [a]

Zdenek Sekanina and Rainer Kracht published a study in 2016 where they concluded that the Lick object is highly likely a fragment of the same parent body as the comet C/1847 C1 (Hind). [2] Their findings suggested that the Lick Object and C/1847 C1 splitted from a parent body sometime during their perihelion on the 7th millennium BC at a relative velocity of ~1.0–1.5 m/s (3.3–4.9 ft/s). [2]

References

Notes

  1. Reported initial position upon discovery was: α = 9h 22m, δ = 15.5° [4]

Citations

  1. 1 2 S. I. Bailey (9 August 1921). "Bright Object near Sun". Harvard College Observatory Bulletin. 757.
  2. 1 2 3 4 Z. Sekanina; R. Kracht (2016). "Pairs and Groups of Genetically Related Long-Period Comets and Probable Identity of the Mysterious Lick Object of 1921". The Astrophysical Journal. 823 (1). arXiv: 1510.06445 . doi: 10.3847/0004-637X/823/1/2 .
  3. 1 2 J. A. Pearce (1921). "The Unidentified Bright Object Seen Near the Sun, August 7, 1921". Journal of the Royal Astronomical Society of Canada. 15: 364–367. Bibcode:1921JRASC..15..364P.
  4. 1 2 W. W. Campbell. "Observations of an Unidentified Object Seen Near the Sun on Sunday, August 7, 1921" (PDF). Publications of the Astronomical Society of the Pacific. 33 (195): 258–260. JSTOR   40668524 .