J. Strader

The Transients and Pulsars with MeerKAT (TRAPUM) project discovered eight binary millisecond pulsars in its first shallow \textit{L}-band survey of unidentified \textit{Fermi} $\gamma$-ray sources using the MeerKAT radio telescope. We…

Redback pulsars are a subclass of millisecond pulsar system with a low-mass non-degenerate companion star being ablated by the pulsar. They are of interest due to the insights they can provide for late-stage pulsar evolution during the…

We investigate the foreground interstellar medium along the line of sight and intracluster medium of $\omega$ Centauri ($\omega$ Cen) by measuring the equivalent width of Na I D absorptions from MUSE observations. The large line-of-sight…

A subset of galaxies have dense nuclei, and when these galaxies are accreted and tidally stripped, the nuclei can masquerade as globular clusters in the halos of large galaxies. If these nuclei contain massive central black holes, some may…

We present a comprehensive photometric and spectroscopic study of the Type IIP SN 2018is. The $V$-band luminosity and the expansion velocity at 50 days post-explosion are $-$15.1$\pm$0.2 mag (corrected for A$_V$=1.34 mag) and 1400 km…

We report on spectroscopic and photometric observations of the AM CVn system ASASSN-21br, which was discovered in outburst by the All-Sky Automated Survey for Supernovae in February 2021. The outburst lasted for around three weeks, and…

We present the results of a high angular resolution (1.1") and sensitivity (maximum of ~0.1 mJy) radio survey at 1-2 GHz in the Galactic Bulge. This complements the X-ray Chandra Galactic Bulge Survey, and investigates the full radio source…

We present the first results from the Revealing Low-Luminosity Active Galactic Nuclei (ReveaLLAGN) survey, a JWST survey of seven nearby LLAGN. We focus on two observations with the Mid-Infrared Instrument's (MIRI) Medium Resolution…

Spider pulsars continue to provide promising candidates for neutron star mass measurements. Here we present the discovery of PSR~J1910$-$5320, a new millisecond pulsar discovered in a MeerKAT observation of an unidentified…

The black hole transient GRS 1915+105 entered a new phase of activity in 2018, generally characterised by low X-ray and radio fluxes. This phase has been only interrupted by episodes of strong and variable radio emission, during which high…

The optical spectra of novae are characterized by emission lines from the hydrogen Balmer series and either Fe II or He/N, leading to their traditional classification into two spectral classes: "Fe II" and "He/N". For decades, the origins…

Using multi-frequency Very Long Baseline Interferometer (VLBI) observations, we probe the jet size in the optically thick hard state jets of two black hole X-ray binary (BHXRB) systems, MAXI J1820+070 and V404 Cygni. Due to optical depth…

We present early spectral observations of the very slow Galactic nova Gaia22alz, over its gradual rise to peak brightness that lasted 180 days. During the first 50 days, when the nova was only 3--4 magnitudes above its normal brightness,…

Over the past decade, observations of relativistic outflows from outbursting X-ray binaries in the Galactic field have grown significantly. In this work, we present the first detection of moving and decelerating radio-emitting outflows from…

We present new radial velocity measurements from the Magellan and the Anglo-Australian Telescopes for 174 previously known and 122 newly confirmed globular clusters (GCs) around NGC 5128, the nearest accessible massive early-type galaxy at…

The conditions under which accreting neutron stars launch radio-emitting jets and/or outflows are still poorly understood. The ultracompact X-ray binary X1850--087, located in the globular cluster NGC 6712, is a persistent atoll-type X-ray…

We catalog the 443 bright supernovae discovered by the All-Sky Automated Survey for Supernovae (ASAS-SN) in $2018-2020$ along with the 519 supernovae recovered by ASAS-SN and 516 additional $m_{peak}\leq18$ mag supernovae missed by ASAS-SN.…

We present new radio and X-ray observations of two nearby ($< 4$ Mpc) low-mass early-type galaxies with dynamically-confirmed central black holes: NGC 5102 and NGC 205. NGC 5102 shows a weak nuclear X-ray source and has no core radio…

We present the first estimate of the Galactic nova rate based on optical transient surveys covering the entire sky. Using data from the All-Sky Automated Survey for Supernovae (ASAS-SN) and \textit{Gaia} -- the only two all-sky surveys to…

We present a detailed study of the 2019 outburst of the cataclysmic variable V1047~Cen, which hosted a classical nova eruption in 2005. The peculiar outburst occurred 14 years after the classical nova event and lasted for more than 400…