When is the best time to observe Lambda Hydrae?

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

Where is Lambda Hydrae located in the sky?

Lambda Hydrae lies in the constellation Hydra at right ascension 10h 11m and declination -12° 21′.

What telescope do I need to split Lambda Hydrae?

Splitting Lambda Hydrae requires an aperture of roughly 60 mm or larger — the components are separated by about 110.0″ at magnitudes near 3.6. The companion is about 8.2 magnitudes fainter, so glare from the primary — not separation — sets the minimum aperture. Larger apertures and steady seeing help resolve the pair cleanly.

Lambda Hydrae — Double Star in Hydra

DoubleStar Hydra (Hya) Visible

Star Map + List + Plan

Observe

1Physical Properties

Magnitude 3.61

Spectral Type K0III CN+1

Star Color Orange (B-V 1.01)

Distance 112 ly

2Position & Identifiers

RA 10h 10m 35.3s

Dec -12° 21' 15.0"

Constellation Hydra (Hya)

HR 3994

HIP 49841

HD 88284

Bayer Lambda

Flamsteed 41 Hya

Double Cat 7671

SIMBAD

3How easy to split?

Primary 3.6 mag Companion 11.8 mag Separation 110.0″

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

Easy Medium Hard Very hard Impossible

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

4Visibility

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Best season Jan – Mar (peak: Feb)

5Multiple Star System Triple optical

Components 3 (triple)

Component IDs AC

Separation 110.0″

Companion Mag 11.8

Position Angle 157°

Star Colors A: Orange

Discoverer BU 593

Notes

Visual companions both optical.

Separation over time

Measured 1902 → 2015 (113 y)

Separation drift 111.9" → 110.0" (-1.90")

Rate -0.0168" / y

PA drift 169° → 157° (-12°, -0.106°/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.