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Phi Sagittarii — Star in Sagittarius

Magnitude 3.2m Star Sagittarius (Sgr) Visible
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1Physical Properties

Magnitude 3.17
Spectral Type B7IV subgiant
Star Color Blue-white (B-V -0.11)
Distance 239 ly

2Position & Identifiers

RA 18h 45m 39.4s
Dec -26° 59' 27.0"
Constellation Sagittarius (Sgr)
HR 7039
HIP 92041
HD 173300
SAO 187239
Bayer Phi
Flamsteed 27 Sgr
SIMBAD

3How easy to spot?

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Equipment Bortle 3 Bortle 4 Bortle 5
Naked eye Easy Easy 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 May – Jul (peak: Jun)

5Survey Image

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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

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15Stellar Notes

4.1, 4.1v, sep. 0.13", doubtful.
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.

Nunki
HIP 92855; Sigma Sagittarii; 34 Sagittarii
Easy
Hot blue O-type star
Star mag 2.02 2.3° Sagittarius
NGC 6638
Easy
Globular cluster — dense ball of ancient stars
Globular Cluster mag 9.2 3.6° Sagittarius
Collinder 394
Easy
Open cluster
Open Cluster mag 6.3 7.0° Sagittarius
V3879 Sgr
Medium
Semi-regular variable, range 6.0–6.6
Variable Star mag 6.35 7.7° Sagittarius
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