J/ApJ/742/112 All quiescent magnitudes for CI Aql and U Sco (Schaefer, 2011)
The change of the orbital periods across eruptions and the ejected mass
for recurrent novae CI Aquilae and U Scorpii.
Schaefer B.E.
<Astrophys. J., 742, 112 (2011)>
=2011ApJ...742..112S 2011ApJ...742..112S (SIMBAD/NED BibCode)
ADC_Keywords: Novae ; Photometry, UBVRIJKLMNH
Keywords: novae, cataclysmic variables - stars: individual (U Sco, CI Aql)
Abstract:
I report on the cumulative results from a program started 24 years ago
designed to measure the orbital period change of recurrent novae (RNe)
across an eruption. The goal is to use the orbital period change to
measure the mass ejected during each eruption as the key part of
trying to measure whether the RNe white dwarfs are gaining or losing
mass over an entire eruption cycle, and hence whether they can be
progenitors for Type Ia supernovae. This program has now been
completed for two eclipsing RNe: CI Aquilae (CI Aql) across its
eruption in 2000 and U Scorpii (U Sco) across its eruption in 1999.
For CI Aql, I present 78 eclipse times from 1991 to 2009 (including
four during the tail of the 2000 eruption) plus two eclipses from 1926
and 1935. For U Sco, I present 67 eclipse times, including 46 times
during quiescence from 1989 to 2009, plus 21 eclipse times in the
tails of the 1945, 1999, and 2010 eruptions. The eclipse times during
the tails of eruptions are systematically and substantially shifted
with respect to the ephemerides from the eclipses in quiescence, with
this being caused by shifts of the center of light during the
eruption. These eclipse times are plotted on an O-C diagram and
fitted to models with a steady period change (dP/dt) between
eruptions (caused by, for example, conservative mass transfer) plus an
abrupt period change (ΔP) at the time of eruption. The primary
uncertainty arises from the correlation between ΔP with dP/dt,
such that a more negative dP/dt makes for a more positive ΔP.
For CI Aql, the best fit is ΔP=-3.7+9.2-7.3x10-7. For U Sco,
the best fit is ΔP=(+43±69)x10-7 days. These period changes
can directly give a dynamical measure of the mass ejected (Mejecta)
during each eruption with negligible sensitivity to the stellar masses
and no uncertainty from distances. For CI Aql, the 1σ upper
limit is Mejecta<10x10-7 M☉. For U Sco, I derive
Mejecta=(43±67)x10-7 M☉.
Description:
Since 1987, I have accumulated a large number of observations of CI Aql
and U Sco in quiescence. Unfortunately, my U Sco observations from
1987 (Schaefer 1988ApJ...327..347S 1988ApJ...327..347S) were not recoverable from magnetic
tape, and it is ironic that century-older astronomical plates still
show the U Sco field. Most of the observations were made as time
series photometry, where repeated CCD images were taken in rapid
succession throughout eclipses. For CI Aql, I report a total of 4960
magnitudes on 387 nights. For U Sco, I report a total of 2382
magnitudes on 116 nights. Each CCD image underwent the standard
processing (bias subtraction, flat fielding) and quality checks (e.g.,
bad columns, poor signal-to-noise ratio). Photometry was all performed
with the APPHOT package in IRAF, which is fine for the uncrowded
stars. The RN magnitudes were all performed differentially with
respect to a suite of three comparison stars, with explicit coordinates
and BVRIJHK magnitudes as given in Schaefer (2010, J/ApJS/187/275).
Objects:
-----------------------------------------------------
RA (ICRS) DE Designation(s)
-----------------------------------------------------
16 22 30.80 -17 52 43.2 U Sco = NOVA Sco 1863
18 52 03.57 -01 28 39.4 CI Aql = NOVA Aql 1917
-----------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table3.dat 48 4960 All Quiescent Magnitudes for CI Aql
(from erratum 2014, ApJ, 781, 127)
table4.dat 48 2382 All Quiescent Magnitudes for U Sco
(from erratum 2014, ApJ, 781, 127)
--------------------------------------------------------------------------------
See also:
J/MNRAS/374/372 : ZYJHK photometry in Upper Sco (Lodieu+, 2007)
J/ApJS/187/275 : Photometric histories of recurrent novae (Schaefer, 2010)
J/ApJ/742/113 : Photometry during the 2010 eruption of U Sco
(Schaefer+, 2011)
J/A+A/544/A26 : CI Aql spectra during 2000 outburst (Iijima, 2012)
J/A+A/559/A121 : U Sco outburst and pre-outburst optical spectrum
(Anupama, 2013)
J/ApJ/795/8 : Nova CI Aql MMO light curve data (Wilson+, 2014)
J/ApJ/811/32 : BVRcIcJHK and X-ray LCs of the U Sco nova (Pagnotta+, 2015)
Byte-by-byte Description of file: table3.dat table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 F12.4 d HJD Heliocentric Julian Date of the observation
14- 29 A16 --- Band Photometric passband
31 A1 --- l_mag [>] Limit flag on mag
33- 37 F5.2 mag mag Observed magnitude in mag
39- 42 F4.2 mag e_mag The 1σ uncertainty in mag
44- 48 F5.3 --- Phase Orbital phase
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 22-Aug-2017