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17 Delphini — Star in Delphinus

Magnitude 5.2m Star Delphinus (Del) Visible
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1Physical Properties

Magnitude 5.17
Spectral Type K0III giant
Star Color Orange (B-V 1.12)
Distance 192 ly

2Position & Identifiers

RA 20h 55m 36.7s
Dec +13° 43' 17.0"
Constellation Delphinus (Del)
HR 8011
HIP 103294
HD 199253
SAO 106665
Flamsteed 17 Del
SIMBAD

3How easy to spot?

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

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Best season Jun – Aug (peak: Jul)

5Survey Image

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6

Size Comparison

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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

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14

Light Travel Time Machine

15

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 7006
Medium+
Globular cluster — dense ball of ancient stars
Globular Cluster mag 10.6 2.8° Delphinus
Gamma Del
HIP 102532; Gamma2 Delphini; 12 Delphini
Easy
Colorful double, sep 8.8″
Double Star mag 4.27 3.2° Delphinus
U Del
Easy
Semi-regular variable, range 6.1–7.6
Variable Star mag 6.38 5.0° Delphinus
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