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 — Asteroide in Sagittarius

14 Irene

Asteroid Sagittarius Visibile

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

Mappa stellare Sistema Solare 3D + Lista + Piano

Proprietà

Magnitudine 8.6

Descrizione

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.

Posizione e identificatori

RA 18h 04m 09.6s

Dec -20° 03' 31.7"

Costellazione Sagittarius

Catalogo Irene

Wikipedia

Proprietà fisiche

Diametro 152 km

Massa 5.6e18 kg

Albedo 0.16 (16% reflected)

Rotazione 15.0 hours

Dimensione angolare 0.1″ (current)

Proprietà orbitali

Semiasse maggiore 2.5879 AU (387.1 million km)

Eccentricità 0.1627

Inclinazione 9.13°

Periodo orbitale 4.16 years

Distanza 1.605 AU (13.4 light-min)

Elongazione 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.