Menu

4 Orionis — Star in Orion

Magnitude 4.7–4.9m Star Orion (Ori) Visible
Star Map
+ List + Plan

Observe

1Physical Properties

Magnitude 4.74
Range 4.65 - 4.88
Period 30.0 days
Variable Type Semi-Regular Variable (Late-type Giant)
Spectral Type S3.5/1-
Star Color Deep ruby red (B-V 1.84)
Distance 815 ly

2Position & Identifiers

RA 04h 52m 32.0s
Dec +14° 15' 02.0"
Constellation Orion (Ori)
HR 1556
HIP 22667
HD 30959
SAO 94176
Flamsteed 4 Ori
Variable ID Omi1 Ori
SIMBAD

3How easy to spot?

Sign in and configure your equipment and default location to see a personalized row.
Equipment Bortle 3 Bortle 4 Bortle 5
Naked eye Medium+ Medium Hard+
50mm finder Easy Easy Easy
150mm scope 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)

5Survey Image

Loading survey image…

Explore

6

Size Comparison

Querying VizieR for stellar data…
7

Compare Stars

8

Spectral Classification

9

Hertzsprung-Russell Diagram

Loading HR diagram…
Read: The Hertzsprung-Russell Diagram — Reading Stars Like a Map
10

Stellar Lifecycle

11

Blackbody Spectrum

12

Stellar Absorption Spectrum

Simulated absorption spectrum based on spectral type. Hover over lines to identify elements.

13

Stellar Fusion

Discover

14Stellar Notes

SRb 4.65 - 4.88V, about 30d.
Wolf 630 group.
Also classified S4Zr1Ti4 and M3.2IIIas.
15

Light Travel Time Machine

16

Relativistic Travel

Nearby in the Sky

Other targets within a few degrees — pan your scope a little and keep exploring.

Visibility scores assume a 150 mm Newton at Bortle 4.

NGC 1662
Easy
Rich open cluster
Open Cluster mag 6.4 3.5° Orion
HU Tau
Medium+
Eclipsing binary, period 2.1d
Variable Star mag 5.92 7.3° Taurus
Hind's variable nebula
NGC 1555
Medium
Reflection nebula around a bright star
Reflection Nebula mag 9.98 8.8° Taurus
Show on Map

Explore Nightbase

Related knowledge, tools, and stories — no observation planning required.

Arthur Eddington
1919 eclipse expedition confirming general relativity; first theory of stellar interiors; the Eddington limit
Biography
The Life of Stars
From birth in a nebula to spectacular death — how stars are born, shine, swell, and die, and how to read the clues in their starlight.
Article
Orion
Mythology, bright stars, and deep-sky highlights.
Constellation
}