83 citations · 96 across the 4 of their papers we have counts for
4 papers · 1 filter
Through Andromeda and Beyond: AGN Optical Transient 'Sharov21' Revisited
A. Bruce, A. Lawrence, D. McLeod +1
We revisit a notable AGN known as `Sharov21', seen to undergo a dramatic outburst in 1992, brightening by a factor of thirty over a period of approximately one year. A simple micro…
Behaviour of the MgII 2798AA Line Over the Full Range of AGN Variability
David Homan, Chelsea L. Macleod, Andy Lawrence +2
We investigate the responsiveness of the 2798AA Mg II broad emission line in AGN on timescales of several years. Our study is based on a sample of extremely variable AGN as well as…
The 'Big Dipper': The nature of the extreme variability of the AGN SDSS J2232-0806
Daniel Kynoch, Martin J. Ward, Andy Lawrence +3
SDSS J2232-0806 (the 'Big Dipper') has been identified as a 'slow-blue nuclear hypervariable': a galaxy with no previously known active nucleus, blue colours and large-amplitude br…
Changing-Look Quasar Candidates: First Results from Follow-up Spectroscopy of Highly Optically Variable Quasars
Chelsea L. MacLeod, Paul J. Green, Scott F. Anderson +15
Active galactic nuclei (AGN) that show strong rest-frame optical/UV variability in their blue continuum and broad line emission are classified as "changing-look" AGN, or at higher…