Intranight polarization variability in radio-loud and radio-quiet AGN (2009)
Villforth, C., Nilsson, K., Ostensen, R., Heidt, J., Pforr, J.
(Abriged) Intranight polarization variability in AGN has not been studied extensively so far. Studying the variability in polarization makes it possibly to distinguish between different emission...
The O-C diagram of the subdwarf B pulsating star HS2201+2610: detection of a giant planet? (2007)
Silvotti, R., Schuh, S., Janulis, R., Bernabei, S., Ostensen, R., ...
In this article we present the O-C diagram of the hot subdwarf B pulsating star HS2201+2610 after seven years of observations. A secular increase of the main pulsation period,...
Six New ZZ Ceti Stars from the SPY and the HQS Surveys. (2007)
Voss, B., Koester, D., Ostensen, R., Napiwotzki, R., Homeier, D., Reimers, D.
Discovery of seven ZZ Ceti stars using a new photometric selection method. (2006)
Voss, B., Koester, D., Ostensen, R., Kepler, S.O., Napiwotzki, R., Homeier, D., ...
The Mass of the sdB Primary of the Binary HS 2333+3927. (2005)
Heber, U., Drechsel, H., Karl, C., Ostensen, R., Folkes, S.L., Napiwotzki, R., ...
HS 2333 3927: A new sdB dM binary with a large reflection effect (2004)
Heber, U., Drechsel, H., Ostensen, R., Karl, C., Napiwotzki, R., Altmann, M., ...
Discovery of gravity-mode pulsators among subdwarf B stars: PG 1716+426, the class prototype (2004)
Reed, M. D., Green, E. M., Callerame, K., Seitenzahl, I. R., White, B. A., Hyde, E. A., ...
A new class of pulsating subdwarf B stars has recently been announced by Green and coworkers. Here we present a follow-up paper describing our observations and the pulsation structure of the class...
HS 2333 + 3927: a new sdB binary with a large reflection effect. (2004)
Karl, C., Heber, U., Drechsel, H., Napiwotzki, R., Altmann, M., Ostensen, R., ...
“The original publication is available at www.springerlink.com”. Copyright Springer. DOI: 10.1023/B:ASTR.0000044334.98860.ab [Full text of this article is not available in the UHRA]
HS 0705 6700: A new eclipsing sdB binary (2001)
Drechsel, H., Heber, U., Napiwotzki, R., Ostensen, R., Solheim, J.E., Johannessen, F., ...
HS 0705+6700: a new eclipsing sdB binary (2001)
Drechsel, H., Heber, U., Napiwotzki, R., Ostensen, R., Johannessen, F., ...
We report the discovery of an eclipsing binary - HS 0705+6700 - being an sdB star with a faint companion. From its light curve the orbital period of 8263.87 s, the mass ratio of the system q = 0.28,...
Chaty, S., Haswell, C. A., Hynes, R. I., Shrader, C. R., Cui, W., Mauche, C. W., ...
We report here on multiwavelength observations of the two new soft X-ray transients (SXTs) XTE J1859+226 and XTE J1118+480, which we observed with HST/RXTE/UKIRT. For XTE J1118+480 we also used EUVE...
The optical afterglow and host galaxy of GRB 000926 (2001)
Fynbo, J.U., Gorosabel, J., Dall, T.H., Hjorth, J., Pedersen, H., Andersen, M.I., ...
Three photometric methods tested on ground-based data of Q 2237+0305 (1998)
Burud, I., Stabell, R., Magain, P., Courbin, F., Ostensen, R., Refsdal, S., ...
The Einstein Cross, Q~2237+0305, has been photometrically observed in four bands on two successive nights at NOT (La Palma, Spain) in October 1995. Three independent algorithms have been used to...
High resolution optical and near-IR imaging of the quadruple quasar RX J0911.4+0551 (1998)
Burud, I., Courbin, F., Lidman, C., Jaunsen, A., Hjorth, J., Ostensen, R., ...
We report the detection of four images in the recently discovered lensed QSO RX J0911.4+0551. With a maximum angular separation of 3.1", it is the quadruply imaged QSO with the widest known angular...
ESO & NOT photometric monitoring of the Cloverleaf quasar (1997)
Ostensen, R, Remy, M, Lindblad, P O, Refsdal, S, Stabell, R, Surdej, Jean, ...
The Cloverleaf quasar, H1413+117, has been photometrically monitored at ESO (La Silla, Chile) and with the NOT (La Palma, Spain) during the period 1987--1994. All good quality CCD frames have been...
Evidence for Diverse Optical Emission from Gamma-Ray Burst Sources (1997)
Pedersen, H., Jaunsen, A. O., Grav, T., Ostensen, R., Andersen, M. I., Wold, M., ...
Optical Transients from gamma-ray burst sources, in addition to offering a distance determination, convey important information on the physics of the emission mechanism, and perhaps also about the...