When is the best time to observe Algorab?

Algorab is best observed from February through April, with peak visibility during March when it transits around midnight in the Northern Hemisphere.

Where is Algorab located in the sky?

Algorab lies in the constellation Corvus at right ascension 12h 30m and declination -16° 31′.

What telescope do I need to split Algorab?

Splitting Algorab requires an aperture of roughly 60 mm or larger — the components are separated by about 24.2″ at magnitudes near 3.0. The companion is about 5.5 magnitudes fainter, so glare from the primary — not separation — sets the minimum aperture. Larger apertures and steady seeing help resolve the pair cleanly.

Algorab — Double Star in Corvus

HIP 60965; Delta Corvi; 7 Corvi

Magnitude 3.0^m DoubleStar Corvus (Crv) Visible

Star Map + List + Plan

About Algorab

Description

Algorab is a white star of spectral type B9.5V at magnitude 2.95 in Corvus. Located about 87 light-years from Earth, it has a luminosity of roughly 37 times solar. Despite its Delta designation, it is one of the brighter stars in the Corvus quadrilateral. It has a wide optical companion visible in binoculars.

Observing Tips

Algorab forms the southwestern corner of the Corvus quadrilateral, the distinctive four-star sail shape south of Virgo. A faint companion is visible in binoculars about 24 arcseconds away. Best observed March through June.

History

The name Algorab comes from the Arabic 'al-ghurab,' meaning 'the crow,' referring to the entire constellation. Corvus is one of the 48 Ptolemaic constellations, compact and easy to recognize.

Fun Facts

The Corvus quadrilateral is one of the handiest asterisms in the spring sky for star-hopping to galaxies — extending a line through Gamma and Delta Crv points roughly toward the Sombrero Galaxy (M104).

Observe

1Physical Properties

Magnitude 2.95

Spectral Type A0.5V

Star Color Blue-white (B-V -0.05)

Distance 87 ly

2Position & Identifiers

RA 12h 29m 51.9s

Dec -16° 30' 56.0"

Constellation Corvus (Crv)

HR 4757

HIP 60965

HD 108767

SAO 157323

Bayer Delta

Flamsteed 7 Crv

Double Cat 8572

SIMBAD Wikipedia

3How easy to split?

Primary 3.0 mag Companion 8.5 mag Separation 24.2″

Telescope	Bortle 3	Bortle 4	Bortle 5
80 mm refractor 80mm refr.	Easy	Easy	Medium+
150 mm Newton 150mm Newt.	Easy	Easy	Easy
Celestron C8 (203 mm SCT) C8 203mm	Easy	Easy	Easy

Easy Medium Hard Very hard Impossible

Bortle 3 = rural · 4 = outer suburbs · 5 = suburbs

4Visibility

Set a location in User Settings to see visibility data.

Best season Feb – Apr (peak: Mar)

5Multiple Star System

Separation 24.2″

Companion Mag 8.5

Companion Sp K1

Position Angle 216°

Star Colors A: Blue-white B: Orange

Discoverer SHJ 145

Notes

CPM. B is K2Ve, lithium strong.

Separation over time

Measured 1782 → 2020 (238 y)

Separation drift 23.5" → 24.2" (+0.70")

Rate +0.0029" / y

PA drift 216° → 216° (+0°, +0.000°/y)

Essentially fixed on human timescales — the same view your grandchildren will see.

Measured from the WDS observational archive. No orbital solution has been derived — most likely the period is too long to fit an orbit to the available measurement arc.