71 Aquilae

{{Short description|Binary star system in the constellation Aquila}}

{{redirect-distinguish-for|l Aquilae|Lambda Aquilae|the commune in Italy|L'Aquila}}

{{Starbox begin

| name = 71 Aquilae

}}

{{Starbox image

| image=

{{Location mark

|image=Aquila constellation map.svg|alt=|float=center|width=260

|label=|position=right

|mark=Red circle.svg|mark_width=10|mark_link=71 Aquilae

|x=108|y=612

}}

|caption=Location of 71 Aquilae (circled)

}}

{{Starbox observe

| epoch = J2000

| ra = {{RA|20|38|20.28206}}

| dec = {{DEC|-01|06|18.4311}}

| appmag_v = 4.33

| constell = Aquila

}}

{{Starbox character

| class = G7.5 IIIa

| b-v = +0.96

| u-b = +0.68

| r-i = 0.46

| v-r =

| variable =

}}

{{Starbox astrometry

| radial_v = −5.6

| prop_mo_ra = +14.84

| prop_mo_dec = −16.45

| parallax = 9.67

| p_error = 0.75

| parallax_footnote =

| absmag_v = −1.03

}}

{{Starbox orbit

| reference =

| period_unitless = 205.2 days

| axis_unitless = {{val|3.82|0.81|ul=mas}}

| eccentricity = 0.000

| inclination = {{val|147.70|5.90}}

| node = {{val|314.00|1.30}}

| periastron = 2423358.0 HJD

| periarg = 0.00

}}

{{Starbox detail

| component1 = primary

| mass = 3.6

| radius = 16.7

| luminosity = 162

| temperature = 5,046

| metal_fe = −0.03

| gravity = 2.77

| rotational_velocity = 10

| age_myr = 347

| component2 = secondary

| mass2 = 0.88

}}

{{Starbox catalog

| names = BD−01 4016, HD 196574, HIP 101847, HR 7884, SAO 144649.

}}

{{Starbox reference

|Simbad=71+Aql

}}

71 Aquilae (abbreviated 71 Aql) is a binary star in the equatorial constellation of Aquila. 71 Aquilae is its Flamsteed designation though it also bears the Bayer designation l Aquilae. The apparent visual magnitude of the system is 4.33, making it bright enough to be viewed by the naked eye. It has an annual parallax shift of 9.67 mas, which equates to a physical distance of {{Convert|340|ly|pc|abbr=off|lk=on}} from Earth, give or take a 30 light-year margin of error. At this distance, the brightness of the system is diminished by 0.065 in visual magnitude from extinction caused by interstellar gas and dust.

This is a spectroscopic binary system where the presence of an orbiting companion is revealed by shifts in the spectral lines caused by the Doppler effect. The primary component is a giant star with a stellar classification of G7.5 IIIa and is listed as a standard star for that class. The secondary is following a circular orbit with a period of 205.2 days.

References

{{reflist|refs=

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}}

Category:Aquila (constellation)

Category:Spectroscopic binaries

Category:G-type giants