HD 5789 and HD 5788 is a pair of stars comprising abinary star[12] system in the northernconstellation ofAndromeda. Located approximately 151 parsecs (490 ly) away, the primary is a hot, massive blue star with an apparent magnitude of 6.06 while the secondary is slightly smaller and cooler, with an apparent magnitude of 6.76. Both stars aremain-sequence stars, meaning that they are currently fusing hydrogen into helium in their cores. As of 2016, the pair had anangular separation of7.90″ along aposition angle of 195°.[13] While both have a similarproper motion andparallax, there's still no proof that the pair is gravitationally bound.
The fainter secondary component is anA-type main-sequence star with a class of A2 Vn.[6] It shows a projected rotational velocity of 270 km/s and has 2.7 times the Sun's mass. The star shines with 73[9] times the Sun's luminosity at an effective temperature of 9,840 K.[5]
^abAbt, Helmut A.; Morrell, Nidia I. (July 1995), "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars",Astrophysical Journal Supplement,99: 135,Bibcode:1995ApJS...99..135A,doi:10.1086/192182.
^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.
