Observe
1Physical Properties
Magnitude
5.82
Range
5.57 - 5.96
Period
2.5 days
Variable Type
Classical Cepheid (First Overtone)
Spectral Type
F7.5Ib-II
Star Color
Yellow
(B-V 0.56)
2Position & Identifiers
RA
21h 06m 30.3s
Dec
+31° 11' 05.0"
Constellation
Cygnus
(Cyg)
HR
8084
HIP
104185
HD
201078
Variable ID
DT Cyg
Querying VizieR catalog...
3How easy to follow?
Magnitude
5.6 – 6.0 mag
Amplitude
0.4 mag
Period
2.5 d
Type
DCEPS
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| Equipment | Bortle 3 | Bortle 4 | Bortle 5 |
|---|---|---|---|
| Naked eye Naked eye | V. hard+ | V. hard | V. hard |
| 50 mm finder 50mm finder | Hard+ | Hard+ | Hard+ |
| 150 mm telescope 150mm scope | Hard+ | Hard+ | Hard+ |
Easy
Medium
Hard
Very hard
Impossible
Bortle 3 = rural · 4 = outer suburbs · 5 = suburbs
Out of reach for typical amateur telescopes, even at Bortle 3.
4Visibility
Set a location in User Settings to see visibility data.
Best season
Jul – Sep
(peak: Aug)
5Light Curve
6Comparison Stars for DT Cyg (5.6–6.0)
Nearby stable stars for estimating brightness (AAVSO)
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Explore
7
Size Comparison
Querying VizieR for stellar data…
8
Compare Stars
9
Spectral Classification
10
Hertzsprung-Russell Diagram
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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
CDelta 5.57 - 5.96V, 2.499215d. Period varies.
Also classified F5.5-F7Ib-II.
Survey Image
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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.
V389 Cyg
Easy double, sep 3.3″
Double Star
mag 5.59
1.1°
Cygnus
NGC 7013
Bright spiral galaxy
Galaxy
mag 12.0
1.4°
Cygnus
East Veil Nebula
NGC 6992
Supernova remnant
Supernova Remnant
mag 7.0
2.2°
Cygnus
T Vul
Pulsating variable, period 4.4d
Variable Star
mag 5.77
4.4°
Vulpecula
X Cyg
Pulsating variable, period 16.4d
Variable Star
mag 6.47
6.5°
Cygnus
V460 Cyg
Semi-regular variable, range 5.6–7.0
Variable Star
mag 6.07
8.6°
Cygnus
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