Infrared Variability of the Gliese 569B System

Gliese 569B is a multiple brown dwarf system whose exact nature has been the subject of several investigations over the past few years. Interpretation has partially relied on infra-red photometry and spectroscopy of the resolved components of the system. We present seeing limited Ks photometry over four nights, searching for variability in this young low mass substellar system. Our photometry is consistent with other reported photometry, and we report the tentative detection of several periodic signals consistent with rotational modulation due to spots on their surfaces. The five significant periods range from 2.90 hours to 12.8 hours with peak to peak variabilities from 28 mmag to 62 mmag in the Ks band. If both components are rotating with the shortest periods, then their rotation axes are not parallel with each other, and the rotation axis of the Bb component is not perpendicular to the Ba-Bb orbital plane. If Bb has one of the longer rotational periods, then the Bb rotation axis is consistent with being parallel to the orbital axis of the Ba-Bb system.Comment: 22 pages, 7 figures, accepted for publication in the Astrophysical Journa

Quantification of a distributive fluvial system; the Salt Wash DFS of the Morrison Formation, SW USA

Peer reviewedPostprin

Controls on the apex location of large deltas

Acknowledgements and Funding We would like to acknowledge the sponsors of the Fluvial Systems Research Group consortium BP, BG, Chevron, ConocoPhillips and Total. We would like to thank A. Felicia for image generation and database management.Peer reviewedPublisher PD

A Revised Orbital Ephemeris for HAT-P-9b

We present here three transit observations of HAT-P-9b taken on 14 February 2010, 18 February 2010, and 05 April 2010 UT from the University of Arizona's 1.55 meter Kuiper telescope on Mt. Bigelow. Our transit light curves were obtained in the I filter for all our observations, and underwent the same reduction process. All three of our transits deviated significantly (approximately 24 minutes earlier) from the ephemeris of Shporer et al. (2008). However, due to the large time span between our observed transits and those of Shporer et al. (2008), a 6.5 second (2 sigma) shift downwards in orbital period from the value of Shporer et al. (2008) is sufficient to explain all available transit data. We find a new period of 3.922814 +/- 0.000002 days for HAT-P-9b with no evidence for significant nonlinearities in the transit period.Comment: 10 pages, 3 figure

On the Apparent Orbital Inclination Change of the Extrasolar Transiting Planet TrES-2b

On June 15, 2009 UT the transit of TrES-2b was detected using the University of Arizona's 1.55 meter Kuiper Telescope with 2.0-2.5 millimag RMS accuracy in the I-band. We find a central transit time of $T_c = 2454997.76286 \pm0.00035$ HJD, an orbital period of $P = 2.4706127 \pm 0.0000009$ days, and an inclination angle of $i = 83^{\circ}.92 \pm 0.05$, which is consistent with our re-fit of the original I-band light curve of O'Donovan et al. (2006) where we find $i = 83^{\circ}.84 \pm0.05$. We calculate an insignificant inclination change of $\Delta i = -0^{\circ}.08 \pm 0.07$ over the last 3 years, and as such, our observations rule out, at the $\sim 11 \sigma$ level, the apparent change of orbital inclination to $i_{predicted} = 83^{\circ}.35 \pm0.1$ as predicted by Mislis and Schmitt (2009) and Mislis et al. (2010) for our epoch. Moreover, our analysis of a recently published Kepler Space Telescope light curve (Gilliland et al. 2010) for TrES-2b finds an inclination of $i = 83^{\circ}.91 \pm0.03$ for a similar epoch. These Kepler results definitively rule out change in $i$ as a function of time. Indeed, we detect no significant changes in any of the orbital parameters of TrES-2b.Comment: 19 pages, 1 table, 7 figures. Re-submitted to ApJ, January 14, 201

Recognition and importance of amalgamated sandy meander belts in the continental rock record

Date of Acceptance: 27/05/2015 ACKNOWLEDGEMENTS This work was supported by the Fluvial Systems Research Group sponsors BG Group, BP, Chevron, ConocoPhillips, and Total.Peer reviewedPostprintPostprin

Follow-up Observations of the Neptune Mass Transiting Extrasolar Planet HAT-P-11b

We have confirmed the existence of the transiting super Neptune extrasolar planet HAT-P-11b. On May 1, 2009 UT the transit of HAT-P-11b was detected at the University of Arizona's 1.55m Kuiper Telescope with 1.7 millimag rms accuracy. We find a central transit time of T_c = 2454952.92534+/-0.00060 BJD; this transit occurred 80+/-73 seconds sooner than previous measurements (71 orbits in the past) would have predicted. Hence, our transit timing rules out the presence of any large (>200 s) deviations from the ephemeris of Bakos et al. (2009). We obtain a slightly more accurate period of P=4.8878045+/-0.0000043 days. We measure a slightly larger planetary radius of R_p=0.452+/-0.020 R_J (5.07+/-0.22 R_earth) compared to Bakos and co-workers' value of 0.422+/-0.014 R_J (4.73+/-0.16 R_earth). Our values confirm that HAT-P-11b is very similar to GJ 436b (the only other known transiting super Neptune) in radius and other bulk properties.Comment: accepted to ApJ Letters, 11 pages, 2 figures (see Dittmann et al. 2009 ApJ 699 L48-L51