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Sigma Bootis — Star in Boötes

Magnitude 4.5m Star Boötes (Boo) Visible
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1Physical Properties

Magnitude 4.46
Variable Type Delta Scuti (Pulsating)
Spectral Type F2V
Star Color Yellow-white (B-V 0.36)
Distance 48 ly

2Position & Identifiers

RA 14h 34m 40.8s
Dec +29° 44' 42.0"
Constellation Boötes (Boo)
HR 5447
HIP 71284
HD 128167
SAO 83416
Bayer Sigma
Flamsteed 28 Boo
SIMBAD

3How easy to spot?

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Equipment Bortle 3 Bortle 4 Bortle 5
Naked eye Medium+ Medium Medium
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

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Best season Mar – May (peak: Apr)

5Survey Image

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Explore

7

Size Comparison

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8

Compare Stars

9

Spectral Classification

10

Hertzsprung-Russell Diagram

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Read: The Hertzsprung-Russell Diagram — Reading Stars Like a Map
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

Delta Sct?
16

Light Travel Time Machine

17

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.

Izar
HIP 72105; Epsilon Bootis; 36 Bootis
Easy
Tight double — a rewarding split at 2.8″
Double Star mag 2.70 3.5° Boötes
34 Boo
Medium
Semi-regular variable, range 4.7–5.4
Variable Star mag 4.81 3.8° Boötes
NGC 5623
Hard+
Elliptical galaxy
Galaxy mag 13.0 3.9° Boötes
NGC 5466
Easy
Globular cluster — dense ball of ancient stars
Globular Cluster mag 9.1 6.5° Boötes
Show on Map

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Boötes
Mythology, bright stars, and deep-sky highlights.
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