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Complete Census Of Luminous Stellar Variability On Day To Decade Timescales

Title: A Complete Census Of Luminous Stellar Variability On Day To Decade Timescales.
Name(s): Conroy, Charlie, author
Strader, Jay, author
van Dokkum, Pieter, author
Dolphin, Andrew E., author
Weisz, Daniel R., author
Murphy, Jeremiah W., author
Dotter, Aaron, author
Johnson, Benjamin D., author
Cargile, Phillip, author
Type of Resource: text
Genre: Journal Article
Journal Article
Date Issued: 2018-09-10
Physical Form: computer
online resource
Extent: 1 online resource
Language(s): English
Abstract/Description: Stellar photometric variability offers a novel probe of the interior structure and evolutionary state of stars. Here we present a census of stellar variability on day to decade timescales across the color-magnitude diagram (CMD) for 73,000 stars brighter than M-1,M-814 = 5 in the Whirlpool Galaxy (M51). Our Cycle 24 Hubble Space Telescope (HST) program acquired V-606- and I-814-band images over 34 epochs spanning 1 year with pseudo-random cadences enabling sensitivity to periods from days to months. We supplement these data with archival V-and I-band HST data obtained in 1995 and 2005, providing sensitivity to variability on decade timescales. At least 50% of stars brighter than M-1,M-814 = -7 show strong evidence for variability within our Cycle 24 data; among stars with V-606 - I-814 > 2 the variability fraction rises to approximate to 100%. Large amplitude variability (>0.3 mag) on decade timescales is restricted to red supergiants (RSGs) and very luminous blue stars. Both populations display fairly smooth variability on month-year timescales. The Cepheid instability strip is clearly visible in our data, although the variability fraction within this region never exceeds approximate to 10%. The location of variable stars across the CMD broadly agrees with theoretical sources of variability, including the instability strip, RSG pulsational instabilities, long-period fundamental mode pulsations, and radiation-dominated envelopes in massive stars. Our data can be used to place stringent constraints on the precise onset of these various instabilities and their lifetimes and growth rates.
Identifier: FSU_libsubv1_wos_000443836000011 (IID), 10.3847/1538-4357/aad460 (DOI)
Keywords: project, evolution, galaxies, large-magellanic-cloud, massive stars, catalog, galaxies: individual (NGC 5194), long-period variables, pulsation, red supergiants, spaced data, stars: variables: general
Publication Note: The publisher’s version of record is available at
Persistent Link to This Record:
Owner Institution: FSU
Is Part Of: Astrophysical Journal.
Issue: iss. 2, vol. 864

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Conroy, C., Strader, J., Van Dokkum, P., Dolphin, A. E., Weisz, D. R., Murphy, J. W., … Cargile, P. (2018). A Complete Census Of Luminous Stellar Variability On Day To Decade Timescales. Astrophysical Journal. Retrieved from