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Sigma Serpentis — Double Star in Serpens

Observable Double Star Excellent (62/100)

Sep: 43.0", Companion: mag 7.8

Magnitude 4.8m DoubleStar Serpens (Ser) Visible
Star Map
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Observe

1Physical Properties

Magnitude 4.82
Spectral Type F0V
Star Color Yellow-white (B-V 0.34)
Distance 76 ly

2Position & Identifiers

RA 16h 22m 04.4s
Dec +01° 01' 45.0"
Constellation Serpens (Ser)
HR 6093
HIP 80179
HD 147449
SAO 121540
Bayer Sigma
Flamsteed 50 Ser
SIMBAD

3How easy to split?

Primary 4.8 mag Companion 7.8 mag Separation 43.0″
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Telescope Bortle 3 Bortle 4 Bortle 5
80mm refr. Easy Easy Easy
150mm Newt. Easy Easy Easy
C8 203mm Easy Easy Easy
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

Separation 43.0″
Companion Mag 7.8
Companion Sp M2V
Position Angle 132°
Star Colors A: Yellow-white B: Red
Discoverer LUH 11

Eyepiece View

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80x Dawes: 1.9″ TFOV: 0.6°
Realistic = true angular size
N E 132°

A: 4.8 · B: 7.8 · Sep: 43.0″ · PA: 132° · N up, E right

Resolved · Rayleigh: 2.3″ · Dawes: 1.9″ · Eff: 2.3″

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6

Size Comparison

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7

Compare Stars

8

Spectral Classification

9

Hertzsprung-Russell Diagram

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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

Hyades group.
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.

Marfik
Lambda Oph
Hard+
Tight double — a rewarding split at 1.3″
Double Star mag 3.82 2.4° Ophiuchus
37 Her
Easy
Easy double, sep 69.3″
Double Star mag 5.77 5.6° Hercules
M12
NGC 6218
Easy
Large bright globular cluster
Globular Cluster mag 6.7 7.0° Ophiuchus
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