U Sagittarii — Variable Star in Sagittarius
Excellent (62/100)
Observe
1Physical Properties
Magnitude
6.68
Range
6.28 - 7.15
Period
6.7 days
Variable Type
Classical Cepheid
Spectral Type
G1.5Ib
supergiant
Star Color
Orange
(B-V 1.13)
2Position & Identifiers
RA
18h 31m 53.3s
Dec
-19° 07' 30.0"
Constellation
Sagittarius
(Sgr)
HR
6947
HIP
90836
HD
170764
SAO
161571
Variable ID
U Sgr
Querying VizieR catalog...
3How easy to follow?
Magnitude
6.3 – 7.1 mag
Amplitude
0.7 mag
Period
6.75 d
Type
DCEP
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| Equipment | Bortle 3 | Bortle 4 | Bortle 5 |
|---|---|---|---|
| Naked eye Naked eye | V. hard | Imp. | Imp. |
| 50 mm finder 50mm finder | Medium | Medium | Medium |
| 150 mm telescope 150mm scope | Medium | Medium | Medium |
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
May – Jul
(peak: Jun)
5Survey Image
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6Light Curve
7Comparison Stars for U Sgr (6.3–7.1)
Nearby stable stars for estimating brightness (AAVSO)
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Explore
8
Size Comparison
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9
Compare Stars
10
Spectral Classification
11
Hertzsprung-Russell Diagram
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12
Stellar Lifecycle
13
Blackbody Spectrum
14
Stellar Absorption Spectrum
Simulated absorption spectrum based on spectral type. Hover over lines to identify elements.
15
Stellar Fusion
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16Stellar Notes
CDelta 6.34 - 7.08V, 6.744925d. May have blue companion.
M25; in cluster IC 4725 #103.
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.
M25
IC 4725
Rich open cluster
Open Cluster
mag 4.6
0.0°
Sagittarius
IC 4715 C
Noteworthy asterism
Asterism
mag 4.50
1.5°
Sagittarius
21 Sgr
Colorful double, sep 1.7″
Double Star
mag 4.81
2.1°
Sagittarius
Y Sgr
Pulsating variable, period 5.8d
Variable Star
mag 5.75
2.5°
Sagittarius
V3879 Sgr
Semi-regular variable, range 6.0–6.6
Variable Star
mag 6.35
2.6°
Sagittarius
IC 1284
Diffuse nebula
Diffuse Nebula
mag 7.70
3.4°
Sagittarius
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