757 Portlandia

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

{{Infobox planet

| minorplanet= yes

| background= #D6D6D6

| name= 757 Portlandia

| mpc_name= (757) Portlandia

| alt_names= 1908 EJ

| discoverer= Joel Hastings Metcalf

| discovered= 30 September 1908

| discovery_site= Taunton, Massachusetts

| epoch= 31 July 2016 (JD 2457600.5)

| eccentricity= 0.10922

| semimajor= {{Convert|2.3734|AU|Gm|abbr=on}}

| perihelion= {{Convert|2.1142|AU|Gm|abbr=on}}

| aphelion= {{Convert|2.6327|AU|Gm|abbr=on|lk=on}}

| period= 3.66 yr (1335.6 d)

| inclination= 8.1694°

| asc_node= 22.515°

| arg_peri= 44.204°

| mean_anomaly= 133.453°

| dimensions=

| mean_radius= {{val|16.045|0.7}} km

| abs_magnitude= 10.20

| rotation= {{Convert|6.5837|h|d|abbr=on|lk=on}}

| albedo= {{val|0.1427|0.014}}

| magnitude= 12.3 to 15.7

| spectral_type= M

| mean_motion= {{Deg2DMS|0.26955|sup=ms}} / day

| orbit_ref=

| observation_arc= 99.16 yr (36218 d)

| uncertainty= 0

}}

757 Portlandia is a main-belt asteroid 32 km in diameter. It was discovered on 30 September 1908 from Taunton, Massachusetts by the amateur American astronomer Joel E. Metcalf. The asteroid was named for the city of Portland, Maine, where Hastings was a church minister at the time. In November 2015, amateur astronomers captured it with images of comet 67P/Churyumov–Gerasimenko.https://www.facebook.com/photo.php?fbid=10206800415562318 {{User-generated source|certain=yes|date=March 2022}} Portlandia came to opposition in March 2016 at apparent magnitude 13.2.{{citation needed|date=August 2021}}

This body is orbiting at a distance of {{val|2.37|ul=AU}} with a period of {{convert|1335.6|days|years|2|disp=out|abbr=off}} and an eccentricity of 0.109. The orbital plane is inclined at an angle of 8.2° to the plane of the ecliptic. 757 Portlandia is classified as an X-type asteroid and is a core member of the proposed Athor asteroid family, named after 161 Athor. This asteroid spans a girth of {{val|32.89|0.24|u=km}} and is rotating with a period of 6.58 hours. During 2003, the asteroid was observed occulting a star. The resulting chords were used to determine a diameter estimate of 36.7 km.