The Observed Seismic Behavior of the Matahina Dam

On 2 March 1987 the 86 m high Matahina earth dam in the Eastern Bay of Plenty region of New Zealand was shaken by a nearby magnitude 6.3 earthquake. The dam response was recorded by five strong motion accelerometers and a maximum crest level acceleration of 0.42 g was measured. The crest level rockfill settled about 100 mm and moved downstream 250 mm during the earthquake. No major leakage has resulted from the earthquake. The results of the damage investigations are described. A condition probably requiring remedial work has been identified on the left abutment

The Killing of an ‘Angry Black Woman’: Sandra Bland and the Politics of Respectability

On July 13th, 2015, 28-year-old Sandra Bland was pulled over by a police officer in Waller County, TX, for failure to signal a lane change. Around six minutes later, Bland was being slammed and handcuffed to the ground. What happened in these six minutes that caused a minor traffic violation to escalate to what would later be three days in jail, concluding with Bland’s death? Hundreds of years of significations towards black women led to Sandra Bland’s arrest. However, at a time when Bland was perceived to be at her most vulnerable, she resisted. By intentionally not putting out a cigarette, she took back more than 400 years’ worth of agency for black women. Although the circumstances that led to her death in police custody are incredibly important, there will be more of a focus in this essay on the significations that resulted in her arrest and that were given to her after death, including the Black Church’s responsibility in responding to actions of injustice

The Spitzer search for the transits of HARPS low-mass planets - I. No transit for the super-Earth HD 40307b

We have used Spitzer and its IRAC camera to search for the transit of the super-Earth HD 40307b. The transiting nature of the planet could not be firmly discarded from our first photometric monitoring of a transit window because of the uncertainty coming from the modeling of the photometric baseline. To obtain a firm result, two more transit windows were observed and a global Bayesian analysis of the three IRAC time series and the HARPS radial velocities was performed. Unfortunately, any transit of the planet during the observed phase window is firmly discarded, while the probability that the planet transits but that the eclipse was missed by our observations is nearly negligible (0.26%).Comment: Submitted to A&

A photometric study of the hot exoplanet WASP-19b

Context: When the planet transits its host star, it is possible to measure the planetary radius and (with radial velocity data) the planet mass. For the study of planetary atmospheres, it is essential to obtain transit and occultation measurements at multiple wavelengths. Aims: We aim to characterize the transiting hot Jupiter WASP-19b by deriving accurate and precise planetary parameters from a dedicated observing campaign of transits and occultations. Methods: We have obtained a total of 14 transit lightcurves in the r'-Gunn, IC, z'-Gunn and I+z' filters and 10 occultation lightcurves in z'-Gunn using EulerCam on the Euler-Swiss telescope and TRAPPIST. We have also obtained one lightcurve through the narrow-band NB1190 filter of HAWK-I on the VLT measuring an occultation at 1.19 micron. We have performed a global MCMC analysis of all new data together with some archive data in order to refine the planetary parameters and measure the occultation depths in z'-band and at 1.19 micron. Results: We measure a planetary radius of R_p = 1.376 (+/-0.046) R_j, a planetary mass of M_p = 1.165 (+/-0.068) M_j, and find a very low eccentricity of e = 0.0077 (+/-0.0068), compatible with a circular orbit. We have detected the z'-band occultation at 3 sigma significance and measure it to be dF_z'= 352 (+/-116) ppm, more than a factor of 2 smaller than previously published. The occultation at 1.19 micron is only marginally constrained at dF_1190 = 1711 (+/-745) ppm. Conclusions: We have shown that the detection of occultations in the visible is within reach even for 1m class telescopes if a considerable number of individual events are observed. Our results suggest an oxygen-dominated atmosphere of WASP-19b, making the planet an interesting test case for oxygen-rich planets without temperature inversion.Comment: Published in Astronomy & Astrophysics. 11 pages, 11 figures, 4 table

TRAPPIST photometry and imaging monitoring of comet C/2013 R1(Lovejoy): Implications for the origin of daughter species

We report the results of the narrow band photometry and imaging monitoring of comet C/2013 R1 (Lovejoy) with the robotic telescope TRAPPIST (La Silla observatory). We gathered around 400 images over 8 months pre- and post-perihelion between September 12, 2013 and July 6, 2014. We followed the evolution of the OH, NH, CN, C3 , and C2 production rates computed with the Haser model as well as the evolution of the dust production. All five gas species display an asymmetry about perihelion, the rate of brightening being steeper than the rate of fading. The study of the coma morphology reveals gas and dust jets which indicate one or several active zone(s) on the nucleus. The dust, C2 , and C3 morphologies present some similarities while the CN morphology is different. OH and NH are enhanced in the tail direction. The study of the evolution of the comet activity shows that the OH, NH, and C2 production rates evolution with the heliocentric distance is correlated to the dust evolution. The CN and, to a lesser extent, the C3 do not display such a correlation with the dust. These evidences and the comparison with parent species production rates indicate that C2 and C3 on one side and OH and NH on the other side could be -at least partially- released from organic-rich grains and icy grains. On the contrary, all evidences point to HCN being the main parent of CN in this comet.Comment: Accepted for publication in Astronomy & Astrophysics, 10 page

Pushing the precision limit of ground-based eclipse photometry

Until recently, it was considered by many that ground-based photometry could not reach the high cadence sub-mmag regime because of the presence of the atmosphere. Indeed, high frequency atmospheric noises (mainly scintillation) limit the precision that high SNR photometry can reach within small time bins. If one is ready to damage the sampling of his photometric time-series, binning the data (or using longer exposures) allows to get better errors, but the obtained precision will be finally limited by low frequency noises. To observe several times the same planetary eclipse and to fold the photometry with the orbital period is thus generally considered as the only option to get very well sampled and precise eclipse light curve from the ground. Nevertheless, we show here that reaching the sub-mmag sub-min regime for one eclipse is possible with a ground-based instrument. This has important implications for transiting planets characterization, secondary eclipses measurement and small planets detection from the ground.Comment: Transiting Planets Proceeding IAU Symposium No.253, 2008. 7 pages, 4 figure

TRAPPIST: a robotic telescope dedicated to the study of planetary systems

We present here a new robotic telescope called TRAPPIST (TRAnsiting Planets and PlanetesImals Small Telescope). Equipped with a high-quality CCD camera mounted on a 0.6 meter light weight optical tube, TRAPPIST has been installed in April 2010 at the ESO La Silla Observatory (Chile), and is now beginning its scientific program. The science goal of TRAPPIST is the study of planetary systems through two approaches: the detection and study of exoplanets, and the study of comets. We describe here the objectives of the project, the hardware, and we present some of the first results obtained during the commissioning phase.Comment: To appear in Detection and Dynamics of Transiting Exoplanets, Proceedings of Haute Provence Observatory Colloquium (23-27 August 2010), eds. F. Bouchy, R.F. Diaz & C.Moutou, Platypus press 201

\u27My Story Ain’t Got Nothin To Do With You\u27 or Does It?: Black Female Faculty’s Critical Considerations of Mentoring White Female Students

Previous literature on mentoring, specifically that of cross-cultural mentoring, has provided some insight into the intricacy of race in mentoring. However, much of this literature has focused on the mentoring relationship of a White individual mentoring a person of color. This qualitative inquiry critically explores the experiences of six Black female faculty who have mentored White female students in higher education graduate programs, focusing specifically on how they enter into these cross-cultural mentoring relationships. Using Black feminist thought, our findings suggest that while individual Black faculty may have unique experiences entering into mentoring relationships with White female students, a Black feminist standpoint does exist. These faculty members entered into the relationships cautiously and with thought, responding emotionally to the idea of mentoring White students, and screening the students, before formalizing the relationship via a student-centered approach. The findings from this study serve as a starting point in which to better understand faculty of color’s experiences mentoring White students as well as provide implications for both faculty and students who may enter into such a relationship

Research in Brief - \u27My Story Ain’t Got Nothin To Do With You\u27 or Does It?: Black Female Faculty’s Critical Considerations of Mentoring White Female Students

Previous literature on mentoring, specifically that of cross-cultural mentoring, has provided some insight into the intricacy of race in mentoring. However, much of this literature has focused on the mentoring relationship of a White individual mentoring a person of color. This qualitative inquiry critically explores the experiences of six Black female faculty who have mentored White female students in higher education graduate programs, focusing specifically on how they enter into these cross-cultural mentoring relationships. Using Black feminist thought, our findings suggest that while individual Black faculty may have unique experiences entering into mentoring relationships with White female students, a Black feminist standpoint does exist. These faculty members entered into the relationships cautiously and with thought, responding emotionally to the idea of mentoring White students, and screening the students, before formalizing the relationship via a student-centered approach. The findings from this study serve as a starting point in which to better understand faculty of color’s experiences mentoring White students as well as provide implications for both faculty and students who may enter into such a relationship