Observe
1Physical Properties
Magnitude
5.38
Range
5.18 - 5.51
Period
4.5 days
Variable Type
Classical Cepheid (First Overtone)
Spectral Type
F8Ib
Star Color
Orange
(B-V 0.80)
2Position & Identifiers
RA
18h 58m 14.7s
Dec
+17° 21' 39.0"
Constellation
Aquila
(Aql)
HR
7165
HIP
93124
HD
176155
Variable ID
FF Aql
Double Cat
11884
Querying VizieR catalog...
3How easy to follow?
Magnitude
5.2 – 5.7 mag
Amplitude
0.5 mag
Period
4.47 d
Type
DCEPS
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| Equipment | Bortle 3 | Bortle 4 | Bortle 5 |
|---|---|---|---|
| Naked eye Naked eye | Hard | V. hard+ | V. hard |
| 50 mm finder 50mm finder | Medium | Medium | Hard+ |
| 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)
5Light Curve
6Comparison Stars for FF Aql (5.2–5.7)
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
ADS 11884A, CDelta 5.18 - 5.68V, 4.470916d. Magnetic field. Possible blue companion.
Companion blue star?
1435d, K 3.5k/s, V0 -17.4k/s, asini 69.1. RV may also vary in 4109d.
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.
U Sge
Eclipsing binary, period 3.4d
Variable Star
mag 6.58
5.4°
Sagitta
NGC 6738
Open cluster
Open Cluster
mag 8.0
5.8°
Aquila
NGC 6658
Edge-on galaxy
Galaxy
mag 12.9
7.9°
Hercules
R Aql
Mira-type variable, range 5.5–12.0
Variable Star
mag 6.09
9.3°
Aquila
U Vul
Pulsating variable, period 8.0d
Variable Star
mag 7.14
9.6°
Vulpecula
X Oph
Mira-type variable, range 5.9–9.2
Variable Star
mag 6.40
9.8°
Ophiuchus
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Aquila
Mythology, bright stars, and deep-sky highlights.
Constellation
