EW Aquarii
EW Aquarii, or HR 8102, is a variable star in the equatorial constellation of Aquarius. With an apparent visual magnitude that fluctuates around 6.47, it is a dim star near the lower limit of visibility to the naked eye. The star is located at a distance of approximately 439 light years from the Sun based on parallax, but is drifting closer with a radial velocity of −39 km/s. The star is positioned near the ecliptic and thus is subject to lunar occultations. It may be a member of the Hyades Group.

In 1969, HR 8102 was flagged as a suspected metal-lined Delta Delphini star and was catalogued as such. During a search for ultra-short period Cepheid variables in 1974, this star was found to vary in brightness and was determined to be a low amplitude Delta Scuti variable. In 1977, it was catalogued in the 62nd name-list of variable stars with the designation EW Aqr. The star varies between magnitudes 6.41 and 6.48 with a primary period of 2.16 hours. There are three known variation periods of 0.09664, 0.1087, and 0.2121 days with amplitudes of 0.013, 0.010, and 0.007 magnitudes, respectively. The pattern of variations indicate it is a non-radial pulsator.

The stellar classification of EW Aqr is , indicating an F-type Am star of the Delta Delphini type. It has 2.2 times the mass of the Sun and four times the Sun's radius. The star has a high rate of spin, showing a projected rotational velocity of 134 km/s. On average, it is radiating 37 times the luminosity of the Sun from its photosphere at an effective temperature of 7,640 K.
Q6243
variable star
Concept
Q187646
equatorial
Concept
Q8928
constellation
Concept
Q10576
Aquarius
CEL
Q124313
apparent visual magnitude
Concept
Q531
light year
Concept
Q525
Sun
CEL
Q906561
parallax
Concept
Q240105
radial velocity
Concept
Q79852
ecliptic
Concept
Q202746
lunar occultation
Concept
Q1065564
Hyades Group
CEL
Q451152
Delta Delphini star
Concept
Q188593
Cepheid variable
Concept
Q836976
Delta Scuti variable
CEL
Q593448
designation
Concept
Q25377588
stellar classification
Concept
Q25377588
F-type
Concept
Q451152
Am star
Concept
Q180892
mass of the Sun
Concept
Q48440
Sun's radius
Concept
Q6464
projected rotational velocity
Concept
Q843877
luminosity of the Sun
Concept
Q6372
photosphere
Concept
Q854050
effective temperature
Concept
Q5324662
EW Aquarii
CEL
8102-01-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
8102
DATE
1969-01-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
1969
DATE
8102-01-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
8102
DATE
1974-01-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
1974
DATE
1977-01-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
1977
DATE
+6.47^^http://www.w3.org/2001/XMLSchema#decimal
6.47
NUMBER
+39^^http://www.w3.org/2001/XMLSchema#decimal
39
NUMBER
+62^^http://www.w3.org/2001/XMLSchema#decimal
62
NUMBER
+6.41^^http://www.w3.org/2001/XMLSchema#decimal
6.41
NUMBER
+6.48^^http://www.w3.org/2001/XMLSchema#decimal
6.48
NUMBER
+2.16^^http://www.w3.org/2001/XMLSchema#decimal
2.16
NUMBER
+0.096^^http://www.w3.org/2001/XMLSchema#decimal
0.096
NUMBER
+64^^http://www.w3.org/2001/XMLSchema#decimal
64
NUMBER
+0.108^^http://www.w3.org/2001/XMLSchema#decimal
0.108
NUMBER
+7^^http://www.w3.org/2001/XMLSchema#decimal
7
NUMBER
+0.212^^http://www.w3.org/2001/XMLSchema#decimal
0.212
NUMBER
+1^^http://www.w3.org/2001/XMLSchema#decimal
1
NUMBER
+0.013^^http://www.w3.org/2001/XMLSchema#decimal
0.013
NUMBER
+0.010^^http://www.w3.org/2001/XMLSchema#decimal
0.010
NUMBER
+0.007^^http://www.w3.org/2001/XMLSchema#decimal
0.007
NUMBER
+2.2^^http://www.w3.org/2001/XMLSchema#decimal
2.2
NUMBER
+37^^http://www.w3.org/2001/XMLSchema#decimal
37
NUMBER
constellation
type of variable star
instance of