66 citations · 542 across the 18 of their papers we have counts for
18 papers
Discovery of Extreme, Roughly-Daily Superflares on the Recurrent Nova V2487 Oph
Bradley E. Schaefer, Ashley Pagnotta, Seth Zoppelt
V2487 Oph is a recurrent nova with detected eruptions in 1900 and 1998. Startlingly, V2487 Oph shows flares, called `Superflares', with up to 1.10 mag amplitude, fast rises of unde…
Precise Measures of Orbital Period, Before and After Nova Eruption for QZ Aurigae
Bradley E. Schaefer, David Boyd, Geoffrey C. Clayton +7
For the ordinary classical nova QZ Aurigae (which erupted in 1964), we report 1317 magnitudes from 1912--2016, including four eclipses detected on archival photographic plates from…
Nova Scorpius 1437 A.D. is now a dwarf nova, age-dated by its proper motion
Michael M. Shara, Krystian Ilkiewicz, Joanna Mikolajewska +12
Here we report the recovery of the binary underlying the classical nova of 11 March 1437 A.D. whose age is independently confirmed by proper motion-dating, and show that in the 20t…
A Hubble Space Telescope survey for novae in M87. III. Are novae good standard candles 15 days after maximum brightness?
Michael M. Shara, Trisha F. Doyle, Ashley Pagnotta +13
Ten weeks of daily imaging of the giant elliptical galaxy M87 with the Hubble Space Telescope (HST) has yielded 41 nova light curves of unprecedented quality for extragalactic cata…
Non-Detection of Nova Shells Around Asynchronous Polars
Ashley Pagnotta, David Zurek
Asynchronous polars (APs) are accreting white dwarfs (WDs) that have different WD and orbital angular velocities, unlike the rest of the known polars, which rotate synchronously (i…
The 2010 Eruption of the Recurrent Nova U Scorpii: The Multi-Wavelength Light Curve
Ashley Pagnotta, Bradley E. Schaefer, James L. Clem +8
The recurrent nova U Scorpii most recently erupted in 2010. Our collaboration observed the eruption in bands ranging from the Swift XRT and UVOT w2 (193 nm) to K-band (2200 nm), wi…
HST Images Flash Ionization of Old Ejecta by the 2011 Eruption of Recurrent Nova T Pyxidis
Michael M. Shara, David Zurek, Bradley E. Schaefer +8
T Pyxidis is the only recurrent nova surrounded by knots of material ejected in previous outbursts. Following the eruption that began on 2011 April 14.29, we obtained seven epochs…
Investigation of the Progenitors of the Type Ia Supernovae Associated With the LMC Supernova Remnants 0505-67.9 and 0509-68.7
Ashley Pagnotta, Bradley E. Schaefer
Although Type Ia supernovae have been heavily scrutinized due to their use in making cosmological distance estimates, we are still unable to definitively identify the progenitors f…
Identifying and Quantifying Recurrent Novae Masquerading as Classical Novae
Ashley Pagnotta, Bradley E. Schaefer
Recurrent novae (RNe) are cataclysmic variables with two or more nova eruptions within a century. Classical novae (CNe) are similar systems with only one such eruption. Many of the…
The Diffuse Source at the Center of LMC SNR 0509-67.5 is a Background Galaxy at z = 0.031
Ashley Pagnotta, Emma S. Walker, Bradley E. Schaefer
Type Ia supernovae (SNe Ia) are well-known for their use in the measurement of cosmological distances, but our continuing lack of concrete knowledge about their progenitor stars is…
The Progenitor of the Type Ia Supernova that created SNR 0519-69.0 in the Large Magellanic Cloud
Zachary I. Edwards, Ashley Pagnotta, Bradley E. Schaefer
Models for the progenitor systems of Type Ia supernovae can be divided into double-degenerate systems, which contain two white dwarfs, and single-degenerate systems, which contain…
The center of the Type Ia supernova remnant SNR 0509-67.5 is empty of any ex-companion star to M_V=+8.4
Bradley E. Schaefer, Ashley Pagnotta
Type Ia supernova (SNe Ia) are thought to originate in the explosion of a white dwarf. The explosion could be triggered by the merger of two white dwarfs ('double-degenerate' origi…
NSV 11154 Is a New R Coronae Borealis Star
Nutsinee Kijbunchoo, Geoffrey C. Clayton, Timothy C. Vieux +7
NSV 11154 has been confirmed as a new member of the rare hydrogen deficient R Coronae Borealis (RCB) stars based on new photometric and spectroscopic data. Using new photometry, as…
Eclipses During the 2010 Eruption of the Recurrent Nova U Scorpii
Bradley E. Schaefer, Ashley Pagnotta, Aaron LaCluyze +34
The eruption of the recurrent nova U Scorpii on 28 January 2010 is now the all-time best observed nova event. We report 36,776 magnitudes throughout its 67 day eruption, for an ave…
Discovery of the 2010 Eruption and the Pre-Eruption Light Curve for Recurrent Nova U Scorpii
Bradley E. Schaefer, Ashley Pagnotta, Limin Xiao +12
We report the discovery by B. G. Harris and S. Dvorak on JD 2455224.9385 (2010 Jan 28.4385 UT) of the predicted eruption of the recurrent nova U Scorpii (U Sco). We also report on…
The Behavior of Novae Light Curves Before Eruption
Andrew C. Collazzi, Bradley E. Schaefer, Limin Xiao +4
In 1975, E. R. Robinson conducted the hallmark study of the behavior of classical nova light curves before eruption, and this work has now become part of the standard knowledge of…
Discovery of a Second Nova Eruption of V2487 Ophiuchi
Ashley Pagnotta, Bradley E. Schaefer, Limin Xiao +2
A directed search for previously-undiscovered nova eruptions was conducted in the astronomical plate archives at Harvard College Observatory and Sonneberg Observatory. We found tha…
The Nova Shell and Evolution of the Recurrent Nova T Pyxidis
Bradley E. Schaefer, Ashley Pagnotta, Michael M. Shara
T Pyxidis is the prototypical recurrent nova (RN) with a mysterious nova shell. We report new observations of the shell with HST. The knots in the shell are expanding with velociti…