C/1925 V1 (Wilk–Peltier)

For other comets discovered by Leslie C. Peltier, see Comet Peltier.

Comet Wilk–Peltier, formal designation C/1925 V1, is a faint hyperbolic comet that was observed through telescopes in late 1925. It was the first comet discovered by American astronomer, Leslie C. Peltier, of which he co-discovered with Polish astronomer, Antoni Wilk.

C/1925 V1 (Wilk–Peltier)

Comet Wilk–Peltier photographed by George van Biesbroeck from the Yerkes Observatory on 10 December 1925[1]
Discovery[2][3]
Discovered by	Antoni Wilk Leslie C. Peltier
Discovery site	Kraków, Poland Delphos, Ohio
Discovery date	13–19 November 1925
Designations
Alternative designations	1925k[4] 1925 XI
Orbital characteristics[5]
Epoch	7 December 1925 (JD 2424491.7674)
Observation arc	40 days
Number of observations	164
Perihelion	0.764 AU
Eccentricity	1.00051
Inclination	144.598°
Longitude of ascending node	141.782°
Argument of periapsis	126.130°
Last perihelion	7 December 1925
Physical characteristics[6][7]
Mean radius	0.449 km (0.279 mi)[a]
Comet total magnitude (M1)	9.6
Apparent magnitude	7.0 (1925 apparition)

Observational history

Discovery

Leslie C. Peltier spotted the comet on the evening of 13 November 1925. He estimated the comet as an 8th or 9th-magnitude object, which at the time was located within the constellation Boötes.^[b] He informed the Harvard College Observatory and the Yerkes Observatory of his discovery to conduct a photographic search on 16–17 November, but failed to see the comet. It was not until Antoni Wilk independently found the same object from Poland on 19 November 1925.^[c]

Although initially uncertain whether or not Peltier and Wilk discovered the same object, Leon Campbell reexamined the photographic plates obtained by the Harvard Observatory and found a faint trail of the comet on the edges of both plates taken on the 16th and 17th, thus confirming their discovery.^[7] At the time, some publications refer to the comet as "Peltier–Wilk" since Peltier was the first to discover the comet.^[8][9][10] It was officially renamed to "Wilk–Peltier" as Wilk's announcement allowed follow-up observations to be conducted by other observatories around the globe.^[2][3]

Follow-up observations

George van Biesbroeck made the last known observations of the comet on 31 December 1925, where he noted it is now a diffuse object that is very low on the horizon as he obtained 3-minute exposures from a 61 cm (24 in) refractor.^[d]

Orbit

On 17 November 1925, Wilk–Peltier made its closest approach to Earth at a distance of 0.5743 AU (85.91 million km). Its first orbital calculations were calculated by C. W. Ebell in 1926, which were later refined by van Biesbroeck,^[11] Richard A. Rossiter,^[12] Louis J. Berman,^[13] and others. Their work reveals the comet had a parabolic trajectory with a perihelion date on 6 December 1925. Later in 1929, Felicjan Kępiński revised this to a weakly hyperbolic trajectory and a perihelion date on December 7th, however he did not apply any planetary perturbations into account.^[14]

See also

• C/1925 F1 (Shajn–Comas Solá)
• C/1925 G1 (Orkisz)