Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Brett M. Morris is active.

Publication


Featured researches published by Brett M. Morris.


Nature Astronomy | 2017

A seven-planet resonant chain in TRAPPIST-1

Rodrigo Luger; Marko Sestovic; Ethan Kruse; Simon L. Grimm; Brice-Olivier Demory; Eric Agol; Emeline Bolmont; Daniel C. Fabrycky; Catarina S. Fernandes; Valérie Van Grootel; Adam J. Burgasser; Michaël Gillon; James G. Ingalls; Emmanuel Jehin; Sean N. Raymond; Franck Selsis; A. H. M. J. Triaud; Geert Barentsen; Steve B. Howell; Laetitia Delrez; Julien de Wit; Daniel Foreman-Mackey; Daniel L. Holdsworth; Jérémy Leconte; Susan M. Lederer; Martin Turbet; Yaseen Almleaky; Z. Benkhaldoun; Pierre Magain; Brett M. Morris

The TRAPPIST-1 system is the first transiting planet system found orbiting an ultra-cool dwarf star. At least seven planets similar to Earth in radius and in mass were previously found to transit this host star. Subsequently, TRAPPIST-1 was observed as part of the K2 mission and, with these new data, we report the measurement of an 18.764 d orbital period for the outermost planet, TRAPPIST-1h, which was unconstrained until now. This value matches our theoretical expectations based on Laplace relations and places TRAPPIST-1h as the seventh member of a complex chain, with three-body resonances linking every member. We find that TRAPPIST-1h has a radius of 0.715 Earth radii and an equilibrium temperature of 169 K, placing it at the snow line. We have also measured the rotational period of the star at 3.3 d and detected a number of flares consistent with an active, middle-aged, late M dwarf.


The Astrophysical Journal | 2013

KEPLER'S OPTICAL SECONDARY ECLIPSE OF HAT-P-7b AND PROBABLE DETECTION OF PLANET-INDUCED STELLAR GRAVITY DARKENING

Brett M. Morris; Avi M. Mandell; Drake Deming

We present observations spanning 355 orbital phases of HAT-P-7 observed by Kepler from 2009 May to 2011 March (Q1-9). We find a shallower secondary eclipse depth than initially announced, consistent with a low optical albedo and detection of nearly exclusively thermal emission, without a reflected light component. We find an approximately 10 ppm perturbation to the average transit light curve near phase –0.02 that we attribute to a temperature decrease on the surface of the star, phased to the orbit of the planet. This cooler spot is consistent with planet-induced gravity darkening, slightly lagging the sub-planet position due to the finite response time of the stellar atmosphere. The brightness temperature of HAT-P-7b in the Kepler bandpass is TB = 2733 ± 21 K and the amplitude of the deviation in stellar surface temperature due to gravity darkening is approximately –0.18 K. The detection of the spot is not statistically unequivocal due its small amplitude, though additional Kepler observations should be able to verify the astrophysical nature of the anomaly.


Monthly Notices of the Royal Astronomical Society | 2016

SDSS J1152+0248: an eclipsing double white dwarf from the Kepler K2 campaign

Na'ama Hallakoun; D. Maoz; Mukremin Kilic; Tsevi Mazeh; A. Gianninas; Eric Agol; Keaton J. Bell; S. Bloemen; Warren R. Brown; John H. Debes; Simchon Faigler; I. Kull; T. Kupfer; Abraham Loeb; Brett M. Morris; Fergal Mullally

We report the discovery of the sixth known eclipsing double white dwarf (WD) system, SDSS J1152+0248, with a 2.3968 +/- 0.0003 h orbital period, in data from the Kepler Missions K2 continuation. Analysing and modelling the K2 data together with ground-based fast photometry, spectroscopy, and radial-velocity measurements, we determine that the primary is a DA-type WD with mass M1 = 0.47 +/- 0.11 Msun, radius R1 = 0.0197 +/- 0.0035 Rsun, and cooling age t1 = 52 +/- 36 Myr. No lines are detected, to within our sensitivity, from the secondary WD, but it is likely also of type DA. Its central surface brightness, as measured from the secondary eclipse, is 0.31 of the primarys surface brightness. Its mass, radius, and cooling age, respectively, are M2 = 0.44 +/- 0.09 Msun, R2 = 0.0223 +0.0064 -0.0050 Rsun, and t2 = 230 +/- 100 Myr. SDSS J1152+0248 is a near twin of the double-lined eclipsing WD system CSS 41177.


The Astronomical Journal | 2018

Astroplan: An open source observation planning package in Python

Brett M. Morris; Erik J. Tollerud; Brigitta Sipőcz; C. Deil; Stephanie T. Douglas; Jazmin Berlanga Medina; Karl Vyhmeister; Toby R. Smith; S. P. Littlefair; Adrian M. Price-Whelan; Wilfred T. Gee; Eric Jeschke

We present astroplan—an open source, open development, Astropy affiliated package for ground-based observation planning and scheduling in Python. astroplan is designed to provide efficient access to common observational quantities such as celestial rise, set, and meridian transit times and simple transformations from sky coordinates to altitude-azimuth coordinates without requiring a detailed understanding of astropys implementation of coordinate systems. astroplan provides convenience functions to generate common observational plots such as airmass and parallactic angle as a function of time, along with basic sky (finder) charts. Users can determine whether or not a target is observable given a variety of observing constraints, such as airmass limits, time ranges, Moon illumination/separation ranges, and more. A selection of observation schedulers are included that divide observing time among a list of targets, given observing constraints on those targets. Contributions to the source code from the community are welcome.


The Astrophysical Journal | 2017

The Starspots of HAT-P-11: Evidence for a Solar-like Dynamo

Brett M. Morris; Leslie Hebb; James R. A. Davenport; Graeme Rohn; Suzanne L. Hawley

We measure the starspot radii and latitude distribution on the K4 dwarf HAT-P-11 from Kepler short-cadence photometry. We take advantage of starspot occultations by its highly-misaligned planet to compare the spot size and latitude distributions to those of sunspots. We find that the spots of HAT-P-11 are distributed in latitude much like sunspots near solar activity maximum, with mean spot latitude of


The Astrophysical Journal | 2017

Toward Space-like Photometric Precision from the Ground with Beam-shaping Diffusers

Gudmundur Stefansson; Suvrath Mahadevan; Leslie Hebb; John P. Wisniewski; Joseph Huehnerhoff; Brett M. Morris; Sam Halverson; Ming Zhao; Jason T. Wright; Joseph G. O’Rourke; Heather A. Knutson; Suzanne L. Hawley; Shubham Kanodia; Yiting Li; Lea M. Z. Hagen; Leo J. Liu; Thomas G. Beatty; Chad F. Bender; Paul Robertson; Jack Dembicky; Candace Gray; William Ketzeback; Russet Jennifer McMillan; Theodore Rudyk

16 pm 1


The Astrophysical Journal | 2017

Chromospheric Activity of HAT-P-11: An Unusually Active Planet-hosting K Star

Brett M. Morris; Suzanne L. Hawley; Leslie Hebb; Charli M. Sakari; James R. A. Davenport; Howard Isaacson; Andrew W. Howard; Benjamin T. Montet; Eric Agol

degrees. The majority of starspots of HAT-P-11 have physical sizes that closely resemble the sizes of sunspots at solar maximum. We estimate the mean spotted area coverage on HAT-P-11 is


The Astrophysical Journal | 2018

Possible Bright Starspots on TRAPPIST-1

Brett M. Morris; Eric Agol; James R. A. Davenport; Suzanne L. Hawley

3^{+6}_{-1}%


Monthly Notices of the Royal Astronomical Society | 2018

Spotting stellar activity cycles in Gaia astrometry

Brett M. Morris; Eric Agol; James R. A. Davenport; Suzanne L. Hawley

, roughly two orders of magnitude greater than the typical solar spotted area.


Astronomy and Astrophysics | 2018

Kepler Object of Interest Network I. First results combining ground- and space-based observations of Kepler systems with transit timing variations

C. von Essen; A. Ofir; S. Dreizler; Eric Agol; J. Freudenthal; Jesús Hernández; S. Wedemeyer; V. Parkash; H. J. Deeg; S. Hoyer; Brett M. Morris; A. C. Becker; L. Sun; S.-H. Gu; E. Herrero; L. Tal-Or; Katja Poppenhaeger; M. Mallonn; S. Albrecht; S. Khalafinejad; P. Boumis; C. Delgado-Correal; Daniel C. Fabrycky; R. Janulis; S. Lalitha; A. Liakos; S. Mikolaitis; M. L. Moyano D'Angelo; E. Sokov; E. Pakstiene

We demonstrate a path to hitherto unachievable differential photometric precisions from the ground, both in the optical and near-infrared (NIR), using custom-fabricated beam-shaping diffusers produced using specialized nanofabrication techniques. Such diffusers mold the focal plane image of a star into a broad and stable top-hat shape, minimizing photometric errors due to non-uniform pixel response, atmospheric seeing effects, imperfect guiding, and telescope-induced variable aberrations seen in defocusing. This PSF reshaping significantly increases the achievable dynamic range of our observations, increasing our observing efficiency and thus better averages over scintillation. Diffusers work in both collimated and converging beams. We present diffuser-assisted optical observations demonstrating 62_(-16)^(+26) ppm precision in 30 minute bins on a nearby bright star 16 Cygni A (V = 5.95) using the ARC 3.5 m telescope—within a factor of ~2 of Keplers photometric precision on the same star. We also show a transit of WASP-85-Ab (V = 11.2) and TRES-3b (V = 12.4), where the residuals bin down to 180_(-41)^(+66) ppm in 30 minute bins for WASP-85-Ab—a factor of ~4 of the precision achieved by the K2 mission on this target—and to 101 ppm for TRES-3b. In the NIR, where diffusers may provide even more significant improvements over the current state of the art, our preliminary tests demonstrated 137_(-36)^(+64) ppm precision for a K_S = 10.8 star on the 200 inch Hale Telescope. These photometric precisions match or surpass the expected photometric precisions of TESS for the same magnitude range. This technology is inexpensive, scalable, easily adaptable, and can have an important and immediate impact on the observations of transits and secondary eclipses of exoplanets.

Collaboration


Dive into the Brett M. Morris's collaboration.

Top Co-Authors

Avatar

Eric Agol

University of Washington

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Leslie Hebb

Hobart and William Smith Colleges

View shared research outputs
Top Co-Authors

Avatar

James R. A. Davenport

Western Washington University

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Gudmundur Stefansson

Pennsylvania State University

View shared research outputs
Top Co-Authors

Avatar

James G. Ingalls

California Institute of Technology

View shared research outputs
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge