When is the best time to observe Upsilon Coronae Borealis?

Upsilon Coronae Borealis is best observed from April through June, with peak visibility during May when it transits around midnight in the Northern Hemisphere.

Where is Upsilon Coronae Borealis located in the sky?

Upsilon Coronae Borealis lies in the constellation Corona Borealis at right ascension 16h 17m and declination +29° 09′.

What telescope do I need to split Upsilon Coronae Borealis?

Splitting Upsilon Coronae Borealis requires an aperture of roughly 60 mm or larger — the components are separated by about 123.1″ at magnitudes near 5.8. The companion is about 4.6 magnitudes fainter, so glare from the primary — not separation — sets the minimum aperture. Larger apertures and steady seeing help resolve the pair cleanly.

Upsilon Coronae Borealis — Double Star in Corona Borealis

DoubleStar Corona Borealis (CrB) Visible

Star Map + List + Plan Star Hop

Observe

1Physical Properties

Magnitude 5.78

Spectral Type A3V

Star Color White (B-V 0.07)

2Position & Identifiers

RA 16h 16m 44.8s

Dec +29° 09' 01.0"

Constellation Corona Borealis (CrB)

HR 6074

HIP 79757

HD 146738

Bayer Upsilon

Flamsteed 18 CrB

Double Cat 9990

SIMBAD

3How easy to split?

Primary 5.8 mag Companion 10.4 mag Separation 123.1″

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

Easy Medium Hard Very hard Impossible

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

4Visibility

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Best season Apr – Jun (peak: May)

5Multiple Star System Quintuple

Components 5 (quintuple)

Component IDs AD

Separation 123.1″

Companion Mag 10.3

Position Angle 50°

Star Colors A: White

Discoverer SHJ 223

Separation over time

Measured 1831 → 2020 (189 y)

Separation drift 128.0" → 123.1" (-4.90")

Rate -0.0259" / y

PA drift 55° → 50° (-5°, -0.026°/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.