Browsing by Author "Wittenmyer, R. A."

Now showing 1 - 6 of 6
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    A DETAILED ANALYSIS OF THE HD 73526 2:1 RESONANT PLANETARY SYSTEM
    (2014) Wittenmyer, R. A.; Tan, X. Y.; Lee, M. H.; Díaz, Marco A.; Horner, J.; Tinney, C. G.; Butler, R. P.; Salter, G. S.; Carter, B. D.; Jones, H. R. A.; O'Toole, S. J.; Bailey, J.; Wright, D.; Crane, J. D.; Schectman, S. A.; Arriagada, P.; Thompson, I.; Minniti, D.
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    HD 76920 b pinned down: A detailed analysis of the most eccentric planetary system around an evolved star
    (2021) Bergmann, C.; Jones, M. I.; Zhao, J.; Mustill, A. J.; Brahm, R.; Torres, P.; Wittenmyer, R. A.; Gunn, F.; Pollard, K. R.; Zapata, A.; Vanzi, L.; Wang, Songhu
    We present 63 new multi-site radial velocity (RV) measurements of the K1III giant HD 76920, which was recently reported to host the most eccentric planet known to orbit an evolved star. We focused our observational efforts on the time around the predicted periastron passage and achieved near-continuous phase coverage of the corresponding RV peak. By combining our RV measurements from four different instruments with previously published ones, we confirm the highly eccentric nature of the system and find an even higher eccentricity of , an orbital period of 415.891(-0.039)(+0.043) d, and a minimum mass of 3.13(-0.43)(+0.41) M-J for the planet. The uncertainties in the orbital elements are greatly reduced, especially for the period and eccentricity. We also performed a detailed spectroscopic analysis to derive atmospheric stellar parameters, and thus the fundamental stellar parameters (M-*, R-*, L-*) taking into account the parallax from Gaia DR2, and independently determined the stellar mass and radius using asteroseismology. Intriguingly, at periastron, the planet comes to within 2.4 stellar radii of its host star's surface. However, we find that the planet is not currently experiencing any significant orbital decay and will not be engulfed by the stellar envelope for at least another 50-80 Myr. Finally, while we calculate a relatively high transit probability of 16%, we did not detect a transit in the TESS photometry.
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    THE SPITZER MICROLENSING PROGRAM AS A PROBE FOR GLOBULAR CLUSTER PLANETS: ANALYSIS OF OGLE-2015-BLG-0448
    (2016) Poleski, Radoslaw; Zhu, Wei; Christie, Grant W.; Udalski, Andrzej; Gould, Andrew; Bachelet, Etienne; Skottfelt, Jesper; Novati, Sebastiano Calchi; Szymanski, M. K.; Soszynski, I.; Pietrzynski, G.; Wyrzykowski, L.; Ulaczyk, K.; Pietrukowicz, P.; Kozlowski, Szymon; Skowron, J.; Mroz, P.; Pawlak, M.; Beichman, C.; Bryden, G.; Carey, S.; Fausnaugh, M.; Gaudi, B. S.; Henderson, C. B.; Pogge, R. W.; Shvartzvald, Y.; Wibking, B.; Yee, J. C.; Beatty, T. G.; Eastman, J. D.; Drummond, J.; Friedmann, M.; Henderson, M.; Johnson, J. A.; Kaspi, S.; Maoz, D.; McCormick, J.; McCrady, N.; Natusch, T.; Ngan, H.; Porritt, I.; Relles, H. M.; Sliski, D. H.; Tan, T. G.; Wittenmyer, R. A.; Wright, J. T.; Street, R. A.; Tsapras, Y.; Bramich, D. M.; Horne, K.; Snodgrass, C.; Steele, I. A.; Menzies, J.; Jaimes, R. Figuera; Wambsganss, J.; Schmidt, R.; Cassan, A.; Ranc, C.; Mao, S.; Bozza, V.; Dominik, M.; Hundertmark, M. P. G.; Jorgensen, U. G.; Andersen, M. I.; Burgdorf, M. J.; Ciceri, S.; D'Ago, G.; Evans, D. F.; Gu, S. H.; Hinse, T. C.; Kains, N.; Kerins, E.; Korhonen, H.; Kuffmeier, M.; Mancini, L.; Popovas, A.; Rabus, M.; Rahvar, S.; Rasmussen, R. T.; Scarpetta, G.; Southworth, J.; Surdej, J.; Unda-Sanzana, E.; Verma, P.; von Essen, C.; Wang, Y. B.; Wertz, O.
    The microlensing event OGLE-2015-BLG-0448 was observed by Spitzer and lay within the tidal radius of the globular cluster NGC 6558. The event had moderate magnification and was intensively observed, hence it had the potential to probe the distribution of planets in globular clusters. We measure the proper motion of NGC 6558 (mu(cl) (N, E) = (+0.36 +/- 0.10, +1.42 +/- 0.10) mas yr(-1)) as well as the source and show that the lens is not a cluster member. Even though this particular event does not probe the distribution of planets in globular clusters, other potential cluster lens events can be verified using our methodology. Additionally, we find that microlens parallax measured using Optical Gravitational Lens Experiment (OGLE) photometry is consistent with the value found based on the light curve displacement between the Earth and Spitzer.
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    TOI-222: a single-transit TESS candidate revealed to be a 34-d eclipsing binary with CORALIE, EulerCam, and NGTS
    (2019) Lendl, M.; Bouchy, F.; Gill, S.; Nielsen, L. D.; Turner, O.; Stassun, K.; Acton, J. S.; Anderson, D. R.; Armstrong, D. J.; Bayliss, D.; Belardi, C.; Bryant, E. M.; Burleigh, M. R.; Chaushev, A.; Casewell, S. L.; Cooke, B. F.; Eigmüller, P.; Gillen, E.; Goad, M. R.; Gunther, M. N.; Hagelberg, J.; Jenkins, J. S.; Louden, T.; Marmier, M.; McCormac, J.; Moyano, M.; Pollacco, D.; Raynard, L.; Tilbrook, R. H.; Udry, S.; Vines, J. I.; West, R. G.; Wheatley, P. J.; Ricker, G.; Vanderspek, R.; Latham, D. W.; Seager, S.; Winn, J.; Jenkins, J. M.; Addison, B.; Briceño, C.; Brahm, R.; Caldwell, D. A.; Doty, J.; Espinoza, N.; Goeke, B.; Henning, T.; Jordán, A.; Krishnamurthy, A.; Law, N.; Morris, R.; Okumura, J.; Mann, A. W.; Rodriguez, J. E.; Sarkis, P.; Schlieder, J.; Twicken, J. D.; Villanueva, S.; Wittenmyer, R. A.; Wright, D. J.; Ziegle, C.
    We report the period, eccentricity, and mass determination for the Transiting Exoplanet Survey Satellite (TESS) single-transit event candidate TOI-222, which displayed a single 3000 ppm transit in the TESS 2-min cadence data from Sector 2. We determine the orbital period via radial velocity measurements (P = 33.9 d), which allowed for ground-based photometric detection of two subsequent transits. Our data show that the companion to TOI-222 is a low-mass star, with a radius of $0.18_{-0.10}^{+0.39}$ R⊙ and a mass of 0.23 ± 0.01 M⊙. This discovery showcases the ability to efficiently discover long-period systems from TESS single-transit events using a combination of radial velocity monitoring coupled with high-precision ground-based photometry.
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    TOI-481 b and TOI-892 b : Two Long-period Hot Jupiters from the Transiting Exoplanet Survey Satellite
    (2020) Brahm, R.; Nielsen, L. D.; Wittenmyer, R. A.; Wang, S. H.; Rodríguez, J. E.; Espinoza, N.; Jones Fernández, Matías Ignacio; Rojas Thomas, Felipe Eduardo; Vanzi, Leonardo; Zapata, Abner; Jordán Colzani, Andrés Cristóbal; Henning, T.; Hobson, M.; Kossakowski, D.; Sarkis, P.; Schlecker, M.; Trifonov, T.; Shahaf, S.; Ricker, G.; Vanderspek, R.; Latham, D. W.; Seager, S.; Winn, J. N.; Jenkins, J. M.; Addison, B. C.; Bakos, G. A.; Bhatti, W.; Bayliss, D.; Berlind, P.; Bieryla, A.; Bouchy, F.; Bowler, B. P.; Briceno, C.; Brown, T. M.; Bryant, E. M.; Caldwell, D. A.; Charbonneau, D.; Collins, K. A.; Davis, A. B.; Esquerdo, G. A.; Fulton, B. J.; Guerrero, N. M.; Henze, C. E.; Hogan, A.; Horner, J; Huang, C. X.; Irwin, J.; Kane, S. R.; Kielkopf, J.; Mann, A. W.
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    TOI-677b : A Warm Jupiter (P=11.2 days) on an Eccentric Orbit Transiting a Late F-type Star
    (2020) Jordán Colzani, Andrés Cristóbal; Brahm Scott, Rafael; Espinoza, N.; Henning, T.; Jones Fernández, Matías Ignacio; Kossakowski, D.; Sarkis, P.; Trifonov, T.; Rojas, F.; Torres, P.; Drass, Holger; Nandakumar, S.; Barbieri, M.; Davis, A.; Wang, S. H.; Bayliss, D.; Bouma, L.; Dragomir, D.; Eastman, J. D.; Daylan, T.; Guerrero, N.; Barclay, T.; Ting, E. B.; Henze, C. E.; Ricker, G.; Vanderspek, R.; Latham, D. W.; Seager, S.; Winn, J.; Jenkins, J. M.; Wittenmyer, R. A.; Bowler, B. P.; Crossfield, I.; Horner, J.; Kane, S. R.; Kielkopf, J. F.; Morton, T. D.; Plavchan, P.; Tinney, C. G.; Addison, B.; Mengel, M. W.; Okumura, J.; Shahaf, S.; Mazeh, T.; Rabus, Markus; Shporer, A.; Ziegler, C.; Mann, A. W.; Hart, R.