U Cephei: an anomalous spectrographic result.

Abstract

view Abstract Citations (16) References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS U Cephei: an anomalous spectrographic result. Carpenter, E. F. Abstract Thirty-four spectrograms of the bright component of the eclipsing variable U Cephei, in spite of broad, shaUow lines and the resulting large probable error of a single observa- tion (13 km/sec.), yielded, by reason of a large range in velocity (220 km/sec.), a satis- factorily defined velocity-curve, the elements from which (Table VI) indicate an orbit of abnormally high eccentricity (0.474) whose major axis is inclined approximately 65° to the line of sight. Earlier photometric data, largely influenced by a shallow secondary minimum near mid-phase, have indicated a circular orbit, but constancy of duration of eclipse and the nature of the variation of the period seem to preclude a reconciliation of the two sets of data by th~ assumption of a rotation of the line of apsides which should bring it into coincidence with the line of sight at the photometric epoch. The period is shown to increase steadily, with an oscifiation of a few seconds' amplitude and an irregu- lar period of about a dozen years. The usual methods for photometric orb~its are extended to include cases where spectrograms have indicated orbits of high eccentricity Publication: The Astrophysical Journal Pub Date: November 1930 DOI: 10.1086/143277 Bibcode: 1930ApJ....72..205C full text sources ADS | data products SIMBAD (1)