The New Milky Way: a wide-field survey of optical transients near the Galactic plane

TL;DR

This paper presents a cost-effective, automated wide-field survey system designed to detect optical transients, including novae, near the Galactic plane within hours, enabling rapid follow-up observations and discovery of fast-evolving astronomical events.

Contribution

The authors developed and demonstrated a low-cost, automated wide-field survey system capable of detecting optical transients in near real-time, significantly reducing detection latency for fast-evolving phenomena.

Findings

Discovered Nova Sagittarii 2012 No. 1 using the system.

Detected two X-ray emitting cataclysmic variables.

Enabled rapid follow-up observations within 22 hours of nova discovery.

Abstract

Currently, it may take days for a bright nova outburst to be detected. With the few exceptions, little is known about novae behaviour prior to maximum light. A theoretically-predicted population of ultra-fast novae with t2<1d is evading observational discovery because it is not possible to routinely organize fast follow-up observations of nova candidates. With the aim of brining the detection time of novae and other bright (V<13.5) optical transients from days down to hours or less, we develop an automated wide-field (8x6 deg.) system capable of surveying the whole Milky Way area visible from the observing site in one night. The system is built using low-cost mass-produced components and the transient detection pipeline is based on the open source VaST software. We describe the instrument design and report results of the first observations conducted in October-November 2011 and January-April 2012. The results include the discovery of Nova Sagittarii 2012 No. 1 as well as two X-ray emitting cataclysmic variables 1RXS J063214.8+25362 and XMMSL1 J014956.7+533504. The rapid detection of Nova Sagittarii 2012 No. 1 enabled us to conduct its X-ray and UV observations with Swift 22 hours after discovery (~31 hour after the outburst onset). All images obtained during the transient search survey are available online.