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200 papers

The detection of the orbital period of 4.36his reported for the new Intermediate Polar 1 WGA 1958.2+3232. The orbital period was derived from time-resolved photometric and spectral observations. We also confirmed the 733 sec spin period of…

Data of 23-years of Jupiter polarimetric observations (1981- 2004) have been reprocessed using new improved technique. The data from other observers have been added to the analysis (1971-74). Anticorrelation between asymmetry of…

We analyse the circular polarisation data accumulated in the first 7 years of the POLAMI project introduced in an accompanying paper (Agudo et al.). In the 3mm wavelength band, we acquired more than 2600 observations, and all but one of our…

We report results from monitoring Pluto's 0.8 to 2.4 {\mu}m reflectance spectrum with IRTF/SpeX on 65 nights over the dozen years from 2001 to 2012. The spectra show vibrational absorption features of simple molecules CH4, CO, and N2…

Earth and Planetary Astrophysics · Physics 2015-06-12 W. M. Grundy , C. B. Olkin , L. A. Young , M. W. Buie , E. F. Young

Here we report on observations of the radio magnetar PSR J1622-4950 at frequencies from 1.4 to 17 GHz. We show that although its flux density is varying up to a factor of ~10 within a few days, it has on average decreased by a factor of 2…

Observations of the optical polarization of NGC 4151 in 1997-2003 show variations of an order of magnitude in the polarized flux while the polarization position angle remains constant. The amplitude of variability of the polarized flux is…

The Parkes multibeam pulsar survey has led to the discovery of more than 700 pulsars. In this paper, we provide timing solutions, flux densities and pulse profiles for 180 of these new discoveries. Two pulsars, PSRs J1736-2843 and…

We present timing observations of four millisecond pulsars, using data obtained over three years at the ATNF Parkes and NRAL Jodrell Bank radio telescopes. Astrometric, spin, and binary parameters are updated, and substantially improved for…

Astrophysics · Physics 2015-06-24 J. F. Bell , M. Bailes , R. N. Manchester , A. G. Lyne , F. Camilo , J. S. Sandhu

The POLAR Investigation of the Sun (POLARIS) mission uses a combination of a gravity assist and solar sail propulsion to place a spacecraft in a 0.48 AU circular orbit around the Sun with an inclination of 75 degrees with respect to solar…

Through an innovative combination of multiple observing techniques and mod- eling, we are assembling a comprehensive understanding of the pulsation and close environment of Cepheids. We developed the SPIPS modeling tool that combines all…

The Parkes multibeam pulsar survey is a sensitive survey of a strip along the Galactic plane with |b|<5 deg and l=260 deg to l=50 deg. It uses a 13-beam receiver on the 64-m Parkes radio telescope, receiving two polarisations per beam over…

We report here on extensive radio observations of the binary system containing PSR B1259-63 and the Be star SS 2883, made around the time of the 2004 periastron. This is the fourth periastron to have been observed in detail. As in previous…

Astrophysics · Physics 2009-11-10 Simon Johnston , Lewis Ball , N. Wang , R. N. Manchester

Attempts to measure extragalactic distances over the last 90 years are briefly described. It follows a short history of the discovery of the expansion of space. Reasons are discussed for the decrease of the Hubble constant from Ho~500…

Astrophysics · Physics 2007-05-23 G. A. Tammann , B. Reindl

An analytical derivation is presented for computing mass-loss rates of Cepheids by using the method of Castor, Abbott, & Klein (1975) modified to include a term for momentum input from pulsation and shocks generated in the atmosphere. Using…

Astrophysics · Physics 2009-11-13 Hilding R. Neilson , John B. Lester

Physical parameters were recently measured for several Cepheids in eclipsing binary systems in the LMC. It is a good opportunity to compare these results with models obtained from pulsation theory. Having well determined physical parameters…

Solar and Stellar Astrophysics · Physics 2018-03-30 Mónica Taormina , Bogumił Pilecki , Radosław Smolec

Analysis of 20 months of observations at the Parkes radio telescope shows secular changes in the pulsed emission from J0737-3039B, the 2.77 s pulsar of the double-pulsar system. Pulse profiles are becoming single-peaked in both bright…

We report VRI CCD observations of nine Cepheids in the South Polar (Sculptor) Group spiral galaxy NGC 0247. Periods of these Cepheids range from 20 to 70 days. Over the past 20 years the very brightest Cepheid in our sample, NGC 0247:[MF09]…

Cosmology and Nongalactic Astrophysics · Physics 2009-01-21 Barry F. Madore , Wendy L. Freedman , J. Catanzarite , Mauricio Navarrete

A typical young pulsar slows down at an imperceptible rate, its spin period increasing by less than 10 microseconds over the course of a year. However, the inertia of a pulsar is so extreme that to effect this tiny change in rotation rate,…

Astrophysics · Physics 2017-08-23 Bryan M. Gaensler

We operate the six German stations of the LOw Frequency ARray as standalone telescopes to observe more than 100 pulsars every week. To date, we have collected almost four years of high-quality data at an unprecedented weekly cadence. This…

Solar and Stellar Astrophysics · Physics 2018-08-22 Caterina Tiburzi , Joris Verbiest

As part of our continuing study of light variability in proto-planetary nebulae (PPNe), we present the results from a long-term study of nine southern hemisphere objects. We have monitored their light variations over a nine-year interval…

Solar and Stellar Astrophysics · Physics 2021-11-24 Bruce J. Hrivnak , Gary Henson , Todd C. Hillwig , Wenxian Lu , Matthew T. Bremer , David M. Vogl , Peyton J. Grimm , Sean M. Egan