Daniel Caton | Appalachian State University (original) (raw)

Papers by Daniel Caton

The Astronomical Journal, Oct 11, 2019

Bulletin of the AAS, Nov 8, 2022

Bulletin of the American Astronomical Society, Oct 1, 2021

Robotic Telescopes, Student Research and Education Proceedings, Vol 1, No 1, Oct 18, 2018

We have two telescopes on the Skynet system at our Dark Sky Observatory (DSO), with hopes to put ... more We have two telescopes on the Skynet system at our Dark Sky Observatory (DSO), with hopes to put on two more existing telescopes. The experience-basically good-of putting telescopes on Skynet for use by faculty, students, and researchers worldwide is described, as well as some of the difficulties of installation and maintenance, and beneficial experiences running them. Our first telescope, a 14-inch Celestron OTA on a Software Bisque Paramount ME German equatorial mount, was a relatively easy installation given its close match to the original Skynet PROMPT telescopes' configuration. The second installation, a 17-inch PlaneWave OTA on a Mathis fork mount, has proven more challenging. We would like to put our 32-inch at DSO, as well as the campus 16-inch, on Skynet but the integral open-loop dome control in the DFM Engineering Telescope Control System presents some problems that are discussed.

Galaxies

We report optical photometric and polarimetric observations of the blazar OJ 287 gathered during ... more We report optical photometric and polarimetric observations of the blazar OJ 287 gathered during 2016/17. The high level of activity, noticed after the General Relativity Centenary flare, is argued to be part of the follow-up flares that exhibited high levels of polarization and originated in the primary black hole jet. We propose that the follow-up flares were induced as a result of accretion disk perturbations, travelling from the site of impact towards the primary SMBH. The timings inferred from our observations allowed us to estimate the propagation speed of these perturbations. Additionally, we make predictions for the future brightness of OJ 287.

Monthly Notices of the Royal Astronomical Society, 2010

The Astronomical Journal, 2015

We present results of a stellar occultation by the Jupiter Trojan asteroid Patroclus and its near... more We present results of a stellar occultation by the Jupiter Trojan asteroid Patroclus and its nearly equal size moon, Menoetius. The geocentric mid-time of the event was 2013 October 21 06:43:02 UT. Eleven sites out of 36 successfully recorded an occultation. Seven chords across Patroclus yielded an elliptical limb fit of 124.6 by 98.2 km. There were six chords across Menoetius that yielded an elliptical limb fit of 117.2 by 93.0 km. There were three sites that got chords on both objects. At the time of the occultation we measured a separation of 664.6 km (0.247 arcsec) and a position angle for Menoetius of 265 •. 7 measured eastward from J2000 north. Combining this occultation data with previous light curve data, the axial ratios of both objects are 1.3 : 1.21 : 1, indicative of a mostly oblate ellipsoid with a slight asymmetry in its equatorial projection. The oblate shape is not an equilibrium shape for the current rotation period, but would be if it were rotating with an ∼8 h period. This faster period is consistent with a pre-evolved state of the system with an orbital separation that is 50% smaller. Our best estimate of the system density is 0.88 g cm −3 .

Binary black hole (BH) central engine description for the unique blazar OJ 287 predicted that the... more Binary black hole (BH) central engine description for the unique blazar OJ 287 predicted that the next secondary BH impact-induced bremsstrahlung flare should peak on 2019 July 31. This prediction was based on detailed general relativistic modeling of the secondary BH trajectory around the primary BH and its accretion disk. The expected flare was termed the Eddington flare to commemorate the centennial celebrations of now-famous solar eclipse observations to test general relativity by Sir Arthur Eddington. We analyze the multi-epoch Spitzer observations of the expected flare between 2019 July 31 and 2019 September 6, as well as baseline observations during 2019 February-March. Observed Spitzer flux density variations during the predicted outburst time display a strong similarity with the observed optical pericenter flare from OJ 287 during 2007 September. The predicted flare appears comparable to the 2007 flare after subtracting the expected higher base-level Spitzer flux densities ...

We report here on a period study and analysis of 2017 BVRcIc light curves of MT Camelopardalis (G... more We report here on a period study and analysis of 2017 BVRcIc light curves of MT Camelopardalis (GSC03737-01085). It is a solar type (T ~ 5500 K) eclipsing binary. It was observed for six nights in December 2017 at Dark Sky Observatory (DSO) with the 0.81-m reflector. Five times of minimum light were calculated from Terrell, Gross, and Cooney’s (2016, IBVS 6166) 2004 and 2016 observations (hereafter TGC). In addition, eleven more times were taken from the literature and six determined from the present observations. From these 15 years of observations a quadratic ephemeris was calculated: JD Hel Min I = 2458103.66121 d + 0.36613905 × E – 0.000000000035 × E2 (2) ±0.00051 ±0.00000021 ±0.000000000015 A BVRcIc filtered simultaneous Wilson-Devinney Program (wd) solution gives a mass ratio (0.3385 ± 0.0014), very nearly the same as TGC’s (0.347 ± 0.003), and a component temperature difference of only ~140 K. As with TGC, no spot was needed in the modeling. Our modeling (beginning with binar...

The Astrophysical Journal