201 Penelope

{{Short description|Main-belt asteroid}}

{{Use dmy dates|date=October 2019}}

{{Infobox planet

| minorplanet = yes

| background = #D6D6D6

| name = 201 Penelope

| image = 201 Penelope.png

| image_scale =

| caption = A three-dimensional model of 201 Penelope based on its light curve.

| discoverer = Johann Palisa

| discovered = 7 August 1879

| mpc_name = (201) Penelope

| pronounced = {{IPAc-en|p|ᵻ|ˈ|n|ɛ|l|ə|p|iː}}{{OED|Penelope}}

| adjective = Penelopean {{IPAc-en|p|ᵻ|ˈ|n|ɛ|l|oʊ|ˈ|p|iː|ə|n}}

| alt_names = A879 PA; 1869 GA

| named_after = Penelópē

| mp_category = Main belt

| epoch = 21 January 2022 (JD 2457600.5)

| semimajor = {{cvt|2.67958|AU|Gm|3|adj=ri3}}

| perihelion = {{cvt|2.19929|AU|Gm|3|adj=ri3}}

| aphelion = {{cvt|3.15987|AU|Gm|3|adj=ri3|lk=on}}

| eccentricity = 0.17924

| period = {{cvt|1602.14|days|years|2|order=flip}}

| inclination = 5.75625°

| asc_node = 156.91554°

| arg_peri = 180.90559°

| mean_anomaly = 169.01173°

| avg_speed = 18.19 km/s

| dimensions = {{val|68.39|3.5|ul=km}}
{{val|87.72|u=km}}

| mass =

| density =

| rotation = {{Convert|3.7474|h|d|abbr=on|lk=on}}

| spectral_type =

{{plainlist|

• Tholen {{=}} M
• SMASS {{=}} X
• B–V {{=}} 0.720
• U–B {{=}} 0.233

}}

| abs_magnitude =

{{plainlist|

• 8.38
• 8.43
• 8.5
• 8.54

}}

| albedo = {{val|0.1604|0.018}}
{{val|0.0881|0.0187|fmt=commas}}

| single_temperature =

| mean_motion = {{Deg2DMS|0.22469930|sup=ms}} / day

| orbit_ref =

| observation_arc = {{cvt|52077|days|years|order=flip}}

| uncertainty = 0

| jupiter_moid = {{Convert|2.23013|AU|Gm|abbr=on}}

| tisserand = 3.347

}}

201 Penelope is a large main belt asteroid that was discovered by Austrian astronomer Johann Palisa on August 7, 1879, in Pola. The asteroid is named after Penelope, the wife of Odysseus in Homer's The Odyssey. It is orbiting the Sun at a distance of {{val|2.68|ul=AU}} with an eccentricity (ovalness) of 0.18 and a period of {{convert|1600.2|days|years|disp=out|abbr=off}}. The orbital plane is tilted at an angle of 5.8° to the plane of the ecliptic.

Based upon the spectra of this object, it is classified as a M-type asteroid, indicating it may be metallic in composition. It may be the remnant of the core of a larger, differentiated asteroid. Near infrared absorption features indicate the presence of variable amounts of low-iron, low-calcium orthopyroxenes on the surface. Trace amounts of water is detected with a mass fraction of about 0.13–0.15 wt%. It has an estimated size of around 88 km. With a rotation period of 3.74 hours, it is the fastest rotating asteroid larger than 50 km in diameter.