This stellar pair have a nearly circular orbit with a
period of nine years and a
semimajor axis of 0.0615
arc seconds.[10] They are both of visual magnitude 5.80 and display a similar
spectrum, with the primary, component A, being an
A-type main sequence star with a
stellar classification of A5 V.[4] This has been identified as an A-type
shell star, suggesting there is a circumstellar disk of gas orbiting one or both stars.[11] There are two other stars that appear close to the pair, termed C and D, but they are physically unrelated.[12]
Ptolemy considered Nu2 Boötis to be shared by
Hercules, and
Bayer assigned it a designation in both constellations: Nu2 Boötis (ν2 Boo) and Psi2 Herculis (ψ2 Her). When the modern constellation boundaries were fixed in 1930, the latter designation dropped from use.[13]
^
abcdJohnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99): 99,
Bibcode:
1966CoLPL...4...99J.
^
abCowley, A.; et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal, 74: 375–406,
Bibcode:
1969AJ.....74..375C,
doi:
10.1086/110819.
This stellar pair have a nearly circular orbit with a
period of nine years and a
semimajor axis of 0.0615
arc seconds.[10] They are both of visual magnitude 5.80 and display a similar
spectrum, with the primary, component A, being an
A-type main sequence star with a
stellar classification of A5 V.[4] This has been identified as an A-type
shell star, suggesting there is a circumstellar disk of gas orbiting one or both stars.[11] There are two other stars that appear close to the pair, termed C and D, but they are physically unrelated.[12]
Ptolemy considered Nu2 Boötis to be shared by
Hercules, and
Bayer assigned it a designation in both constellations: Nu2 Boötis (ν2 Boo) and Psi2 Herculis (ψ2 Her). When the modern constellation boundaries were fixed in 1930, the latter designation dropped from use.[13]
^
abcdJohnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99): 99,
Bibcode:
1966CoLPL...4...99J.
^
abCowley, A.; et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal, 74: 375–406,
Bibcode:
1969AJ.....74..375C,
doi:
10.1086/110819.