What telescope do I need to see Irene?

At magnitude 8.6, Irene is within reach of a 3-inch (80 mm) telescope from a moderate-Bortle site.

Irene — Asteroid in Sagittarius

14 Irene

Asteroid Sagittarius Sichtbar

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

Sternkarte 3D-Sonnensystem + Liste + Plan

Eigenschaften

Helligkeit 8.6

Beschreibung

Type: Asteroid

Distance: 2.588 AU

Orbital Period: 1520.6 days

Diameter: 152 km

Greek goddess of peace; S-type; reaches mag 8.6 at perihelic oppositions, near the binocular limit.

Position & Bezeichnungen

RA 18h 04m 09.6s

Dec -20° 03' 31.7"

Sternbild Sagittarius

Katalog Irene

Wikipedia

Physikalische Eigenschaften

Durchmesser 152 km

Masse 5.6e18 kg

Albedo 0.16 (16% reflected)

Rotation 15.0 hours

Winkeldurchmesser 0.1″ (current)

Bahneigenschaften

Große Halbachse 2.5879 AU (387.1 million km)

Exzentrizität 0.1627

Bahnneigung 9.13°

Umlaufzeit 4.16 years

Entfernung 1.605 AU (13.4 light-min)

Elongation 128.8° 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.