Nova Eruptions from Radio to Gamma-rays—with AAVSO Data in the Middle (Abstract)

Volume 46 number 1 (2018)

Koji Mukai, Stella Kafka, Laura Chomiuk,

Ray Li, Tom Finzell, Justin Linford,

Jeno Sokoloski, Tommy Nelson, Michael Rupen,

Amy Mioduszewski, Jennifer Weston

Address correspondence to: Goddard Space Flight Center, National Aeronautics and Space Administration, Greenbelt, MD 20771; koji.mukai@nasa.gov

Abstract

(Abstract only) Novae are among the longest-known class of optical transients. In recent years, V1369 Cen in the south reached magnitude 3.3 in late 2013, and had repeated (but not periodic) cycles of re-brightening. Earlier in 2013, V339 Del almost reached magnitude 4.0 during the northern summer. An expanding ball of gas, at about 10,000 K, expelled by a nuclear explosion on the surface of a white dwarf, can explain much of the visible light outputs of novae. But these spectacular visible light displays turn out to be just a small part of the show. Novae are also transient objects in the radio through gamma-rays—in addition to the warm, visible light-emitting gas, we need cold dust particles that emit in the infra-red, 10 million degree shock-heated gas that emits hard X-rays, and the exposed surface of the nuclear-burning white dwarf that emits soft X-rays. Last but not least, we need an exotic process of particle acceleration to explain the gamma-rays and some radio data. In recent years, using data from satellites (such as Swift) and ground-based telescopes (including the Jansky VLA), we have made significant progress cataloging and understanding the messy process of mass ejection in novae. But we still know very little about exactly how novae produce gamma-rays. We plan to collect more gamma-ray data using the Fermi satellite over the next several years, of course continue our multi-wavelength observations from the radio to the X-rays as well. For that, we need the AAVSO community to (1) discover novae, as early as possible, and alert us; and (2) monitor novae, particularly brighter ones that are suitable for gamma-ray observations. Even in the era of ASAS-SN and other professional surveys, amateur astronomers are competitive in terms of nova discovery. Once discovered, the sheer number of small telescopes operated by the AAVSO community will provide the optical light curves and, increasingly, optical spectra that are the centerpiece of any study of novae.