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The Inter-eruption Timescale of Classical Novae from Expansion of the Z Camelopardalis Shell

Shara, Michael M. and Mizusawa, Trisha and Zurek, David and Martin, Christopher D. and Neill, James D. and Seibert, Mark (2012) The Inter-eruption Timescale of Classical Novae from Expansion of the Z Camelopardalis Shell. Astrophysical Journal, 756 (2). Art. No. 107. ISSN 0004-637X.

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The dwarf nova Z Camelopardalis is surrounded by the largest known classical nova shell. This shell demonstrates that at least some dwarf novae must have undergone classical nova eruptions in the past, and that at least some classical novae become dwarf novae long after their nova thermonuclear outbursts. The current size of the shell, its known distance, and the largest observed nova ejection velocity set a lower limit to the time since Z Cam's last outburst of 220 years. The radius of the brightest part of Z Cam's shell is currently ~880 arcsec. No expansion of the radius of the brightest part of the ejecta was detected, with an upper limit of ≤0.17 arcsec yr^(–1). This suggests that the last Z Cam eruption occurred ≥5000 years ago. However, including the important effect of deceleration as the ejecta sweeps up interstellar matter in its snowplow phase reduces the lower limit to 1300 years. This is the first strong test of the prediction of nova thermonuclear runaway theory that the interoutburst times of classical novae are longer than 1000 years. The intriguing suggestion that Z Cam was a bright nova, recorded by Chinese imperial astrologers in October-November 77 B.C.E., is consistent with our measurements. If Z Cam was indeed the nova of 77 B.C.E. we predict that its ejecta are currently expanding at 85 km s^(–1), or 0.11 arcsec yr^(–1). Detection and measurement of this rate of expansion should be possible in just a few years.

Item Type:Article
Related URLs:
URLURL TypeDescription
Mizusawa, Trisha0000-0001-7182-5307
Martin, Christopher D.0000-0002-8650-1644
Neill, James D.0000-0002-0466-1119
Seibert, Mark0000-0002-1143-5515
Additional Information:© 2012 American Astronomical Society. Received 2012 May 14; accepted 2012 July 9; published 2012 August 21. M.M.S. gratefully acknowledges helpful conversations with and suggestions from Lars Bildsten, David Kaplan, and Michael Bode.
Group:Space Astrophysics Laboratory
Subject Keywords:novae, cataclysmic variables; stars: individual (Z Cam)
Issue or Number:2
Record Number:CaltechAUTHORS:20121106-120738783
Persistent URL:
Official Citation:The Inter-eruption Timescale of Classical Novae from Expansion of the Z Camelopardalis Shell Michael M. Shara et al. 2012 ApJ 756 107
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:35305
Deposited By: Ruth Sustaita
Deposited On:06 Nov 2012 22:41
Last Modified:09 Apr 2021 19:36

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