HD 74438 is a spectroscopic quadruple stellar system composed of a pair of double star systems approximately 425 light years from Earth, located in open cluster IC 2391.[5][6] With an estimated age of 43+15 −7 million years,[4] HD 74438 is the youngest quadruple star system known.[7] The outer orbital period of the system, estimated at around 5.7 years, is also among the shortest of quadruple systems.[4][7]
^Houk, Nancy (1978). Michigan catalogue of two-dimensional spectral types for the HD stars. Vol. 2. Ann Arbor: Dept. Of Astronomy, University of Michigan. Bibcode:1978mcts.book.....H.
^ abcdefgMerle, Thibault; Hamers, Adrian S.; Van Eck, Sophie; Jorissen, Alain; Van der Swaelmen, Mathieu; Pollard, Karen; Smiljanic, Rodolfo; Pourbaix, Dimitri; Zwitter, Tomaž; Traven, Gregor; Gilmore, Gerry; Randich, Sofia; Gonneau, Anaïs; Hourihane, Anna; Sacco, Germano; Worley, C. Clare (12 May 2022). "A spectroscopic quadruple as a possible progenitor of sub-Chandrasekhar type Ia supernovae". Nature Astronomy. 6 (6): 681–688. arXiv:2205.05045. Bibcode:2022NatAs...6..681M. doi:10.1038/s41550-022-01664-5. S2CID248665714.