About the Book
Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Pages: 24. Chapters: Pegasus, IK Pegasi, List of stars in Pegasus, HD 209458 b, HR 8799, 51 Pegasi b, HR 8799 c, HR 8799 b, HR 8799 d, Messier 15, Pegasus Dwarf Irregular Galaxy, NGC 7331, HR 8799 e, Pegasus Dwarf Spheroidal Galaxy, 85 Pegasi, Epsilon Pegasi, Kappa Pegasi, NGC 7742, NGC 7318, V391 Pegasi, HD 210702, WASP-10b, HAT-P-8b, NGC 1, Einstein Cross, Beta Pegasi, HD 219828, V391 Pegasi b, Alpha Pegasi, NGC 7332, HD 210702 b, NGC 7814, IM Pegasi, BD+14 4559, NGC 7752 and NGC 7753, NGC 7479, Gamma Pegasi, BD+14 4559 b, NGC 2, Theta Pegasi, NGC 7217, Iota Pegasi, NGC 7331 Group, HD 218155, HD 218133, HD 219828 b, NGC 8, NGC 7317, NGC 7319, NGC 7320c, II Pegasi, Zeta Pegasi, NGC 18, NGC 7777, Huchra's Lens, Mu Pegasi, Tau Pegasi, SN 1990U, HD 4. Excerpt: IK Pegasi (or HR 8210) is a binary star system in the constellation Pegasus. It is just luminous enough to be seen with the unaided eye, at a distance of about 150 light years from the Solar System. The primary (IK Pegasi A) is a main sequence, A-class star that displays minor pulsations in luminosity. It is categorized as a Delta Scuti variable star and it has a periodic cycle of luminosity variation that repeats itself about 22.9 times per day. Its companion (IK Pegasi B) is a massive white dwarf-a star that has evolved past the main sequence and is no longer generating energy through nuclear fusion. They orbit each other every 21.7 days with an average separation of about 31 million kilometres, or 19 million miles, or 0.21 astronomical units (AU). This is smaller than the orbit of Mercury around the Sun. IK Pegasi B is the nearest known supernova progenitor candidate. When the primary begins to evolve into a red giant, it is expected to grow to a radius where the white dwarf can accrete matter from the expanded gaseous envelope. When the white dwarf approaches the Chandrasekhar l...
