When is the best time to observe 13 Lacertae?

13 Lacertae is best observed from July through September, with peak visibility during August when it transits around midnight in the Northern Hemisphere.

Where is 13 Lacertae located in the sky?

13 Lacertae lies in the constellation Lacerta at right ascension 22h 44m and declination +41° 49′.

What telescope do I need to split 13 Lacertae?

Splitting 13 Lacertae requires an aperture of roughly 60 mm or larger — the components are separated by about 14.4″ at magnitudes near 5.1. The companion is about 5.8 magnitudes fainter, so glare from the primary — not separation — sets the minimum aperture. Larger apertures and steady seeing help resolve the pair cleanly.

13 Lacertae — Double Star in Lacerta

Magnitude 5.1^m DoubleStar Lacerta (Lac) Visible

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Observe

1Physical Properties

Magnitude 5.08

Spectral Type K0III giant

Star Color Orange (B-V 0.96)

Distance 326 ly

2Position & Identifiers

RA 22h 44m 05.5s

Dec +41° 49' 09.0"

Constellation Lacerta (Lac)

HR 8656

HIP 112242

HD 215373

SAO 52317

Flamsteed 13 Lac

Double Cat 16227

SIMBAD

3How easy to split?

Primary 5.1 mag Companion 10.9 mag Separation 14.4″

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

Easy Medium Hard Very hard Impossible

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

4Visibility

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Best season Jul – Sep (peak: Aug)

5Multiple Star System

Separation 14.4″

Companion Mag 10.9

Position Angle 130°

Star Colors A: Orange

Discoverer STT 479

Notes

Fixed sep.

Separation over time

Measured 1828 → 2012 (184 y)

Separation drift 12.0" → 14.4" (+2.40")

Rate +0.0130" / y

PA drift 133° → 130° (-3°, -0.016°/y)

Slow change over generations — observable in lifetime comparisons.

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.