What telescope do I need to see Interamnia?

At magnitude 9.5, Interamnia is within reach of a 3-inch (80 mm) telescope from a moderate-Bortle site.

Interamnia — Asteroid in Virgo

704 Interamnia

Magnitude 9.5^m Asteroid Virgo Visible

Rendered preview of Interamnia from the Nightbase orrery, lit from the current Sun direction with the terminator visible.

Star Map 3D Solar System + List + Plan

Properties

Magnitude 9.5

Description

Type: Asteroid

Distance: 3.056 AU

Orbital Period: 1951.5 days

Diameter: 332 km

Latin name for Teramo, Italy; F-type; sixth-largest main-belt body, comparable in mass to Pallas.

Position & Identifiers

RA 13h 39m 12.9s

Dec -29° 18' 28.4"

Constellation Virgo

Catalog Interamnia

Wikipedia

Physical Properties

Diameter 332 km

Mass 3.5e19 kg

Albedo 0.08 (8% reflected)

Rotation 8.7 hours

Angular Size 0.2″ (current)

Orbital Properties

Semi-major Axis 3.0562 AU (457.2 million km)

Eccentricity 0.1552

Inclination 17.32°

Orbital Period 5.34 years

Distance 2.724 AU (22.7 light-min)

Elongation 127.2° Good

Brightness Forecast (next 12 months)

Apparent magnitude as Earth–asteroid distance changes through the year. The peak marks the brightest moment in the window — usually around opposition, when the asteroid is closest and fully illuminated.

Computed from JPL orbital elements via m = H + 5·log₁₀(r·Δ). Phase-function correction is omitted, so curves trace distance variation only — accurate within a few tenths for main-belt asteroids; coarse for fast-moving NEOs near Earth.