@article{10272/12243,
year = {2016},
url = {http://hdl.handle.net/10272/12243},
abstract = {We report the results of a long campaign of time-series photome
try on the nova-like variable UX 
Ursae  Majoris  during  2015.  It  spanned  150  nights,  with  ~  1800  h
ours  of  coverage  on  121 
separate nights. The star was in its normal ‘high state’ near m
agnitude 
V
 = 13, with slow waves 
in  the  light  curve  and  eclipses  every  4.72  hours.  Remarkably,  t
he star also showed a nearly 
sinusoidal signal with a full amplitude of 0.44 mag and a perio
d of 3.680± 0.007 d. We interpret 
this as the signature of a retrograde precession (wobble) of th
e accretion disc. The same period is 
manifest as a ±33 s wobble in the timings of mid-eclipse, indic
ating that the disc’s centre of light 
moves with this period. The star also showed strong ‘negative s
uperhumps’ at frequencies ft)
or
b 
+ 
N
 and 2ft)
or
b + N, where w
or
b and 
N
 are respectively the orbital and precession frequencies. It 
is possible that these powerful signals have been present, unsu
spected, throughout the more than 
60 years of previous photometric studies.},
organization = {We thank the National Science Foundation for support of this re
search 
(AST12-11129),  and  also  the  Mount  Cuba  Astronomical  Foundation.
Finally, we thank the American Association of Variable Star Obs
ervers 
(AAVSO)  for  providing  the  infrast
ructure  and  continued  inspirat
ion 
which makes programs like this possible.},
publisher = {Oxford University Press},
title = {Accretion-disc precession in UX Ursae Majoris},
doi = {10.1093/mnras/stv3014},
author = {Miguel Agustino, Enrique de and Patterson, Joseph},
}