Der Lichtwechsel des Ap‐Sterns HD 221568 (Osawas Stern) in zehn Spektralbereichen

Abstract

Zentralinstitut f u r Astrophysik dcr Akadentie clcr Wissenschaften der I>DK l l i t zwci Xbbilduiigeri (Eingegangen 1984 Septentbcr 7) I , l h c jiitcriiicdiate longlieriodic Ap star 111) L L~ jOS has beeit obscrved during the time from 197" till 1981 in ten spectral regions (34jo A --76jo ii). The star shows typical rotational double mavi' li~lttcurves. The properties of the amplitude-wave length relation are siinilar to tliosc of some cooler shortperiodic Ap stars. 'llle cstini;itetl variation of the flux in the visible spectral region indicates espcctcd variability with large aniplitiude in the U V spcctral region. Der schon zu den langpcriodischen Ap-Sternen geliBrende Stern HI) 2 2 I 568 wurdc in1 Zeitraum 1976 bis 1981 in zehn Spektralbereichen (3450 A --76 j o A) beobachtet. Der Stern zeigt typische Rotationslichtkurven rnit einer Doppelwelle. Die Eigenschaften der Amplituden-\Velle~tlangen-Beziehu~tg haben Ahnlichkeit rnit der einiger kiiltler kurzperiodischer Ap-Sterne. Die berechnete Variation des Strahlungsstroins im Sichtbareri dcutct auf cine im ultravioletten zu erwartcnde Variabilitat rnit groller Amplitude hin. Literatur KODAIRA, K . : ~g f q , Astrophys. J . 1 5 7 , L 5').

On the Photometric Variability of Very Sharp-lined Cool mCP Stars

“…Kodaira (1967) carried out an extensive study of the spectrum and found variations of a number of elements, principal among them being the REE, Si, Fe and Cr. Schöneich & Zelwanova (1985) performed 10-color photometry whose variability agreed with the 159.0 day period of Nakagiri & Yamashita (1979) from UBV photometry. We found no published magnetic field measurements.…”

“…The open circles are the same as in Figure 1. The filled triangles are the values of Schöneich & Zelwanova (1985) for U, P, X, Y, and V. The filled circles represent the measurements of Musielok & Madej (1988). The filled squares, open squares, crosses, and filled inverted triangles are the normalized equivalent widths á ñ ( ) W W from Kodaira (1967) for Eu II, Si II, Fe I and Cr I, respectively.…”