21 Aql
Observable Variable Star
Good (51/100)
Range: 5.1 - 5.2, Period: 1.7d, Type: Alpha CV
HIP 94477; 21 Aql
VariableStar
Aql
Visible
Level 3
Medium telescope (6-8") - Monitor brightness changes
Physical Properties
Magnitude
5.15
Variable Type
Alpha2 CVn (Magnetic Rotating)
Spectral Type
B8II-III
Star Color
Blue-white
(B-V -0.07)
Distance
362.4 ly
Position & Identifiers
RA
19h 13m 42.7s
Dec
+02° 17' 37.0"
Constellation
Aql
HR
7287
HIP
94477
Flamsteed
21 Aql
Variable ID
V1288 Aql
Double Cat
12182
Querying VizieR catalog...
Visibility
Set a location in User Settings to see visibility data.
Comparison Stars for 21 Aql (5.1–5.2)
Nearby stable stars for estimating brightness (AAVSO)
Loading comparison stars…
Multiple Star System
Separation
36.9″
Companion Mag
12.3
Position Angle
287°
Star Colors
A: Blue-white
Discoverer
HJ 879
Eyepiece View
80x
Dawes: 1.9″
TFOV: 0.6°
Realistic = true angular size
Sep: 36.9″ · PA: 287° · N up, E left
Resolved · Rayleigh: 2.3″ · Dawes: 1.9″ · Eff: 3.1″
Size Comparison
Querying VizieR for stellar data…
Stellar Lifecycle
Spectral Classification
Hertzsprung-Russell Diagram
Loading HR diagram…
Blackbody Spectrum
Stellar Absorption Spectrum
Simulated absorption spectrum based on spectral type. Hover over lines to identify elements.
Stellar Notes
Alpha CV 5.06 - 5.16V, 1.73d.
Companion optical.
Survey Image
Loading survey image…