Observe
1Physical Properties
Magnitude
5.68
Range
5.12 - 6.65
Period
80 days
Variable Type
Semi-Regular Variable (Late-type Giant)
Spectral Type
M6III
Star Color
Red
(B-V 1.46)
2Position & Identifiers
RA
05h 11m 22.8s
Dec
-11° 50' 57.0"
Constellation
Lepus
(Lep)
HR
1693
HIP
24169
HD
33664
Variable ID
RX Lep
Querying VizieR catalog...
3How easy to follow?
Magnitude
5.0 – 7.4 mag
Amplitude
2.4 mag
Period
79.54 d
Type
SRB
Sign in
and configure your equipment and default location to see a personalized row.
| Equipment | Bortle 3 | Bortle 4 | Bortle 5 |
|---|---|---|---|
| Naked eye Naked eye | V. hard | V. hard | Imp. |
| 50 mm finder 50mm finder | Easy | Easy | Medium+ |
| 150 mm telescope 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
Nov – Jan
(peak: Dec)
5Light Curve
6Comparison Stars for RX Lep (5.0–7.4)
Nearby stable stars for estimating brightness (AAVSO)
Loading comparison stars…
Explore
7
Size Comparison
Querying VizieR for stellar data…
8
Compare Stars
9
Spectral Classification
10
Hertzsprung-Russell Diagram
Loading HR diagram…
11
Stellar Lifecycle
12
Blackbody Spectrum
13
Stellar Absorption Spectrum
Simulated absorption spectrum based on spectral type. Hover over lines to identify elements.
14
Stellar Fusion
Discover
15Stellar Notes
SRb 5.0 - 7.4v, 60:d.
Survey Image
Loading survey image…
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 1784
Bright spiral galaxy
Galaxy
mag 11.8
1.5°
Lepus
R Lep
Mira-type variable, range 5.5–11.7
Variable Star
mag 7.71
4.1°
Lepus
Mu Lep
Variable star, range 3.0–3.4
Variable Star
mag 3.31
4.4°
Lepus
66 Eri
Variable star, range 5.1–5.6
Variable Star
mag 5.12
7.3°
Eridanus
M42
NGC 1976
Emission nebula — try an OIII filter
Emission Nebula
mag 4.0
8.7°
Orion
V1031 Ori
Eclipsing binary, period 3.4d
Variable Star
mag 6.03
8.9°
Orion
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
Variable Stars — A Guide for Observers
A practical guide to visual observation of variable stars: estimating magnitudes, finding comparison stars, recording data, and contributing to science with AAVSO.
Article
Lepus
Mythology, bright stars, and deep-sky highlights.
Constellation
