C/2014 B1 (Schwartz)

C/2014 B1 (Schwartz) is a distant hyperbolic comet with a perihelion distance of 9.56 AU (1.430 billion km) from the Sun.

C/2014 B1 (Schwartz)

Discovery[1]
Discovered by	Michael B. Schwartz
Discovery site	Tenagra Observatory
Discovery date	28 January 2014
Orbital characteristics[2]
Epoch	16 February 2018 (JD 2458165.5)
Observation arc	8.24 years
Number of observations	1,276
Perihelion	9.557 AU
Eccentricity	1.00321
Inclination	28.376°
Longitude of ascending node	161.39°
Argument of periapsis	345.86°
Last perihelion	10 September 2017
Earth MOID	8.575 AU
Jupiter MOID	4.231 AU
Physical characteristics[3][4][5]
Mean radius	6.364±0.214 km
Spectral type	(V–R) = 0.93±0.19
Comet total magnitude (M1)	6.2
Apparent magnitude	15.0 (2017 apparition)

Observational history

Discovery

American astronomer, Michael B. Schwartz, discovered the comet in the early evening of 28 January 2014 using an astrograph from the Tenagra Observatory near Nogales, Arizona.^[1] At the time of discovery, it was about 12.0 AU (1.80 billion km) from the Sun. Subsequent observations from several other observatories across the world confirmed its cometary nature on 29 January.^[1]

Follow-up observations

The comet reached perihelion on September 2017, reaching its maximum recorded brightness as a 15th-magnitude object.^[3] In 2021, the comet was already 1.61 billion km (1.00 billion mi) from Earth and was observed near the galaxy PGC 48046, where it was expected to remain brighter than magnitude 20.0 until 2023 at the earliest.^[6]

Physical characteristics

Observations from the NEOWISE mission revealed that due to the comet's large perihelion distance, which is too cold for water ice to sublimate, cometary activity in this object is mostly driven by carbon dioxide and carbon monoxide gases.^[7] This phenomenon is also observed from other comets with similarly distant perihelia, like C/2010 U3 and C/2017 K2.^[7]

It is noted that from ground observations, the comet had a morphologically stable discus-shaped coma, which had increased in brightness by 1.0 by the time it reached perihelion in 2017.^[8]

Initial estimates of the size of its nucleus in 2019 were roughly 2–10 km (1.2–6.2 mi) in radius.^[8] Reanalysis of a 2017 photographic observation of the comet about a year later has refined its effective radius to 6.364±0.214 km, using a new method where the absolute brightness of the nucleus is inferred from the measured brightness distribution in the coma using a mathematical model.^[5]

Spectral and polarimetric observations of the comet from the Smithsonian Astrophysical Observatory (SAO) reveal the color of the jet structures is much redder than that of the ambient coma, and the nucleus itself also has a reddish color.^[4][9]