Publications (31)
Radio Astronomy and eVLBI using KAREN
Stuart Weston, Tim Natusch, Sergei Gulyaev
Kiwi Advanced Research and Education Network (KAREN) has been used to transfer large volumes of radio astronomical data between the AUT Radio Astronomical Observatory at Warkworth,…
OGLE-2017-BLG-0406: Microlens Parallax Reveals Saturn-mass Planet orbiting M-dwarf Host in the Inner Galactic Disk
Yuki Hirao, David P. Bennett, Yoon-Hyun Ryu +93
We report the discovery and analysis of the planetary microlensing event OGLE-2017-BLG-0406, which was observed both from the ground and by the satellite in a solar…
First scientific VLBI observations using New Zealand 30 metre radio telescope WARK30M
Leonid Petrov, Tim Natusch, Stuart Weston +3
We report the results of a successful 24 hour 6.7 GHz VLBI experiment using the 30 meter radio telescope WARK30M near Warkworth, New Zealand, recently converted from a radio teleco…
MOA-2020-BLG-208Lb: Cool Sub-Saturn Planet Within Predicted Desert
Greg Olmschenk, David P. Bennett, Ian A. Bond +74
We analyze the MOA-2020-BLG-208 gravitational microlensing event and present the discovery and characterization of a new planet, MOA-2020-BLG-208Lb, with an estimated sub-Saturn ma…
The First Data Release of CNIa0.02 -- A Complete Nearby (Redshift <0.02) Sample of Type Ia Supernova Light Curves
Ping Chen, Subo Dong, C. S. Kochanek +41
The CNIa0.02 project aims to collect a complete, nearby sample of Type Ia supernovae (SNe Ia) light curves, and the SNe are volume-limited with host-galaxy redshifts z_host < 0.02.…
Spica and the annual cycle of PKS B1322-110 scintillations
Hayley Bignall, Cormac Reynolds, Jamie Stevens +9
PKS B1322-110 is a radio quasar that is located only 8.5' in angular separation from the bright B star Spica. It exhibits intra-day variability in its flux density at GHz frequenci…
Microlensing Parallax for OGLE-2017-BLG-0896 Reveals a Counter-Rotating Low-Mass Brown Dwarf
Yossi Shvartzvald, Jennifer C. Yee, Jan Skowron +63
The kinematics of isolated brown dwarfs in the Galaxy, beyond the solar neighborhood, is virtually unknown. Microlensing has the potential to probe this hidden population, as it ca…
New Zealand involvement in Radio Astronomical VLBI Image Processing
Stuart Weston, Tim Natusch, Sergei Gulyaev
With the establishment of the AUT University 12m radio telescope at Warkworth, New Zealand has now become a part of the international Very Long Baseline Interferometry (VLBI) commu…
Spitzer Microlensing parallax reveals two isolated stars in the Galactic bulge
Weicheng Zang, Yossi Shvartzvald, Tianshu Wang +90
We report the mass and distance measurements of two single-lens events from the 2017 Spitzer microlensing campaign. The ground-based observations yield the detection of finite-sour…
Warkworth 12-m VLBI Station: WARK12M
Sergei Gulyaev, Tim Natusch, Stuart Weston +2
This report summarizes the geodetic VLBI activities in New Zealand in 2010. It provides geographical and technical details of WARK12M - the new IVS network station operated by the…
Observations of radio sources near the Sun
Oleg Titov, Sebastien Lambert, Benedikt Soja +15
Geodetic Very Long Baseline Interferometry (VLBI) data are capable of measuring the light deflection caused by the gravitational field of the Sun and large planets with high accura…
KMT-2022-BLG-1818Lb,c: A Cold Super-Jupiter with a Saturn Sibling
Hongyu Li, Jiyuan Zhang, Cheongho Han +72
We present the discovery and analysis of the sixth microlensing two-planet system, KMT-2022-BLG-1818Lb,c, detected by a follow-up program targeting high-magnification events. Both…
A Linear Relation Between the Color Stretch and the Rising Color Slope of Type Ia Supernovae
Ping Chen, Subo Dong, Chris Ashall +34
Using data from the Complete Nearby () sample of Type Ia Supernovae (CNIa0.02), we discover a linear relation between two parameters derived from the color cur…
OGLE-2017-BLG-1186: first application of asteroseismology and Gaussian processes to microlensing
Shun-Sheng Li, Weicheng Zang, Andrzej Udalski +102
We present the analysis of the event OGLE-2017-BLG-1186 from the 2017 Spitzer microlensing campaign. This is a remarkable microlensing event because its source is photometrically b…
A Detailed Observational Analysis of V1324 Sco, the Most Gamma-Ray Luminous Classical Nova to Date
Thomas Finzell, Laura Chomiuk, Brian D. Metzger +32
It has recently been discovered that some, if not all, classical novae emit GeV gamma rays during outburst, but the mechanisms involved in the production of the gamma rays are stil…
First geodetic observations using new VLBI stations ASKAP-29 and WARK12M
Leonid Petrov, Chris Phillips, Tasso Tzioumis +11
We report the results of a successful 7 hour 1.4 GHz VLBI experiment using two new stations, ASKAP-29 located in Western Australia and WARK12M located on the North Island of New Ze…
Inverse MultiView II: Microarcsecond Trigonometric Parallaxes for Southern Hemisphere 6.7~GHz Methanol Masers G232.62+00.99 and G323.7400.26
Lucas J. Hyland, Mark J. Reid, Gabor Orosz +11
We present the first results from the Southern Hemisphere Parallax Interferometric Radio Astrometry Legacy Survey (\spirals): as-accurate parallaxes and proper motions for tw…
Gaia22dkvLb: A Microlensing Planet Potentially Accessible to Radial-Velocity Characterization
Zexuan Wu, Subo Dong, Tuan Yi +50
We report discovering an exoplanet from following up a microlensing event alerted by Gaia. The event Gaia22dkv is toward a disk source rather than the traditional bulge microlensin…
Warkworth 12-m VLBI Station: WARK12M - 2012
Stuart Weston, Hiroshi Takiguchi, Tim Natusch +1
The Warkworth 12-m Radio Telescope is operated by the Institute for Radio Astronomy and Space Research (IRASR) at AUT University, Auckland, New Zealand. This report briefly reviews…
Application of Lossless Data Compression Techniques to Radio Astronomy Data flows
Tim Natusch
The modern practice of Radio Astronomy is characterized by extremes of data volume and rates, principally because of the direct relationship between the signal to noise ratio that…
KMT-2021-BLG-0171Lb and KMT-2021-BLG-1689Lb: Two Microlensing Planets in the KMTNet High-cadence Fields with Followup Observations
Hongjing Yang, Weicheng Zang, Andrew Gould +56
Follow-up observations of high-magnification gravitational microlensing events can fully exploit their intrinsic sensitivity to detect extrasolar planets, especially those with sma…
OGLE-2019-BLG-0960Lb: The Smallest Microlensing Planet
Jennifer C. Yee, Weicheng Zang, Andrzej Udalski +80
We report the analysis of OGLE-2019-BLG-0960, which contains the smallest mass-ratio microlensing planet found to date (q = 1.2--1.6 x 10^{-5} at 1-sigma). Although there is substa…
New Zealand pathway towards Asia-Pacific and global e-VLBI research and development
Sergei Gulyaev, Tim Natusch, Stuart Weston +1
Over the past 3 years, Auckland University of Technology has established the first radio astronomical observatory in New Zealand, which, because of its remote geographic location,…
Conversion of New Zealand's 30m Telecommunication Antenna into a Radio Telescope
Lewis Woodburn, Tim Natusch, Stuart Weston +3
We describe our approach to the conversion of a former 100-foot (30-m) telecommunication antenna in New Zealand into a radio telescope. We provide the specifications of the Earth S…
KMT-2021-BLG-2010Lb, KMT-2022-BLG-0371Lb, and KMT-2022-BLG-1013Lb: Three microlensing planets detected via partially covered signals
Cheongho Han, Chung-Uk Lee, Weicheng Zang +25
We inspect 4 microlensing events KMT-2021-BLG-1968, KMT-2021-BLG-2010, KMT-2022-BLG-0371, and KMT-2022-BLG-1013, for which the light curves exhibit partially covered short-term cen…
Warkworth 12m VLBI Station: WARK12M - 2014
Stuart Weston, Tim Natusch, Lewis Woodburn +2
The Warkworth Radio Astronomical Observatory is operated by the Institute for Radio Astronomy and Space Research (IRASR), AUT University, Auckland, New Zealand. Here we review the…
An Isolated Stellar-Mass Black Hole Detected Through Astrometric Microlensing
Kailash C. Sahu, Jay Anderson, Stefano Casertano +90
We report the first unambiguous detection and mass measurement of an isolated stellar-mass black hole (BH). We used the Hubble Space Telescope (HST) to carry out precise astrometry…
The TANAMI Multiwavelength Program: Dynamic SEDs of Southern Blazars
Felicia KrauÃ, Joern Wilms, Matthias Kadler +32
Simultaneous broadband spectral and temporal studies of blazars are an important tool for investigating active galactic nuclei (AGN) jet physics. We study the spectral evolution be…
First Resolution of Microlensed Images of a Binary-Lens Event
Zexuan Wu, Subo Dong, A. Mérand +72
We resolve the multiple images of the binary-lens microlensing event ASASSN-22av using the GRAVITY instrument of the Very Large Telescope Interferometer (VLTI). The light curves sh…
Systematic KMTNet Planetary Anomaly Search. VIII. Complete Sample of 2019 Subprime Field Planets
Youn Kil Jung, Weicheng Zang, Hanyue Wang +41
We complete the publication of all microlensing planets (and ``possible planets'') identified by the uniform approach of the KMT AnomalyFinder system in the 21 KMT subprime fields…
Unprecedented change in the position of four radio sources
Oleg Titov, Sándor Frey, Sébastien Lambert +7
Astrometric positions of radio-emitting active galactic nuclei (AGNs) can be determined with sub-milliarcsec accuracy using very long baseline interferometry (VLBI). The usually sm…