When is the best time to observe Sigma Tauri?

Sigma Tauri is best observed from October through December, with peak visibility during November when it transits around midnight in the Northern Hemisphere.

Where is Sigma Tauri located in the sky?

Sigma Tauri lies in the constellation Taurus at right ascension 04h 39m and declination +15° 55′.

What telescope do I need to split Sigma Tauri?

Splitting Sigma Tauri requires an aperture of roughly 60 mm or larger — the components are separated by about 444.0″ at magnitudes near 4.7. Larger apertures and steady seeing help resolve the pair cleanly.

Sigma Tauri — Double Star in Taurus

HIP 21683; Sigma2 Tauri; 92 Tauri

Observable Double Star Good (52/100)

Sep: 444.0", Companion: mag 5.1

Magnitude 4.7^m DoubleStar Taurus (Tau) Visible

Star Map + List + Plan

Observe

1Physical Properties

Magnitude 4.69

Spectral Type A5Vn

Star Color Yellow-white (B-V 0.15)

Distance 163 ly

2Position & Identifiers

RA 04h 39m 16.5s

Dec +15° 55' 05.0"

Constellation Taurus (Tau)

HR 1479

HIP 21683

HD 29488

SAO 94054

Bayer Sigma2

Flamsteed 92 Tau

SIMBAD Wikipedia

3How easy to split?

Primary 4.7 mag Companion 5.1 mag Separation 444.0″

Sign in and configure your equipment and default location to see a personalized row.

Telescope	Bortle 3	Bortle 4	Bortle 5
80 mm refractor 80mm refr.	Easy	Easy	Easy
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 Oct – Dec (peak: Nov)

5Multiple Star System Triple

Components 3 (triple)

Component IDs AB

Separation 444.0″

Companion Mag 5.1

Companion Sp A4m

Position Angle 194°

Star Colors A: Yellow-white B: White

Discoverer STFA 11

Notes

Binary with HR 1478.

Separation over time

Measured 1836 → 2014 (178 y)

Separation drift 427.4" → 444.0" (+16.60")

Rate +0.0933" / y

PA drift 192° → 194° (+2°, +0.011°/y)

Apparent motion is significant on a human timescale — worth revisiting in a decade.

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.