Browsing by Author "Udalski, A."

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    A super-jupiter orbiting a late-type star : a refined analysis of microlensing event OGLE-2012-BLG-0406
    (2014) Tsapras, Y.; Choi, J.-Y; Street, R.; Han, C.; Bozza, V.; Gould, A.; Dominik, M.; Beaulieu, J. P.; Udalski, A.; Rabus, Markus
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    An analysis of binary microlensing event OGLE-2015-BLG-0060
    (2019) Tsapras, Y.; Cassan, A.; Ranc, C.; Bachelet, E.; Street, R.; Udalski, A.; Hundertmark, M.; Bozza, V.; Beaulieu, J. P.; Rabus, Markus; Marquette, J. B.; Euteneuer, E.; Bramich, D. M.; Dominik, M.; Jaimes, R. F.; Horne, K.; Mao, S.; Menzies, J.; Schmidt, R.; Snodgrass, C.; Steele, I. A.; Wambsganss, J.; Mroz, P.; Szymanski, M. K.; Soszynski, I.; Skowron, J.; Pietrukowicz, Pawel; Kozlowski, S.; Poleski, R.; Ulaczyk, K.; Pawlak, M.; Jorgensen, U. G.; Skottfelt, J.; Popovas, A.; Ciceri, S.; Korhonen, H.; Kuffmeier, M.; Evans, D. F.; Peixinho, N.; Hinse, T. C.; Burgdorf, M. J.; Southworth, J.; Tronsgaard, R.; Kerins, E.; Andersen, M. I.; Rahvar, S.; Wang, Y.; Wertz, O.; Novati, S. C.; D'Ago, G.; Scarpetta, G.; Mancini, L.; Abe, F.; Asakura, Y.; Bennett, D. P.; Bhattacharya, A.; Donachie, M.; Evans, P.; Fukui, A.; Hirao, Y.; Itow, Y.; Kawasaki, K.; Koshimoto, N.; Li, M. C. A.; Ling, C. H.; Masuda, K.; Matsubara, Y.; Muraki, Y.; Miyazaki, S.; Nagakane, M.; Ohnishi, K.; Rattenbury, N.; Saito, T.; Sharan, A.; Shibai, H.; Sullivan, D. J.; Sumi, T.; Suzuki, D.; Tristram, P. J.; Yamada, T.; Yonehara, A.
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    Faint-source-star planetary microlensing: the discovery of the cold gas-giant planet OGLE-2014-BLG-0676Lb
    (2017) Rabus, Markus; Rattenbury, N. J.; Bennett, D. P.; Sumi, T.; Koshimoto, N.; Udalski, A.; Shvartzvald, Y.; Maoz, D.; Jorgensen, U. G.; Street, R. A.; Tsapras, Y.; Abe, F.; Asakura, Y.; Barry, R.; Bhattacharya, A.; Suzuki, D.
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    MASS. MEASUREMENTS. OF. ISOLATED. OBJECTS. FROM. SPACE-BASED. MICROLENSING
    (2016) Zhu, W.; Novati, S.; Gould, A.; Udalski, A.; Han, C.; Shvartzvald, Y.; Ranc, C.; Jorgensen, U.; Poleski, R.; Rabus, Markus; Bozza, V.; Beichman, C.; Bryden, G.; Carey, S.; Gaudi, B.; Henderson, C.
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    Massive stars exploding in a He-rich circumstellar medium - V. Observations of the slow-evolving SN Ibn OGLE-2012-SN-006
    (2015) Pastorello, A.; Wyrzykowski, L.; Valenti, S.; Prieto, J. L.; Kozlowski, S.; Udalski, A.; Elias-Rosa, N.; Morales-Garoffolo, A.; Anderson, J. P.; Benetti, S.; Bersten, M.; Botticella, M. T.; Cappellaro, E.; Fasano, G.; Fraser, M.; Gal-Yam, A.; Gillone, M.; Graham, M. L.; Greiner, J.; Hachinger, S.; Howell, D. A.; Inserra, C.; Parrent, J.; Rau, A.; Schulze, S.; Smartt, S. J.; Smith, K. W.; Turatto, M.; Yaron, O.; Young, D. R.; Kubiak, M.; Szymanski, M. K.; Pietrzynski, G.; Soszynski, I.; Ulaczyk, K.; Poleski, R.; Pietrukowicz, P.; Skowron, J.; Mroz, P.
    We present optical observations of the peculiar Type Ibn supernova (SN Ibn) OGLE-2012-SN-006, discovered and monitored by the Optical Gravitational Lensing Experiment-IV survey, and spectroscopically followed by Public ESO Spectroscopic Survey of Transient Objects (PESSTO) at late phases. Stringent pre-discovery limits constrain the explosion epoch with fair precision to JD = 245 6203.8 +/- 4.0. The rise time to the I-band light-curve maximum is about two weeks. The object reaches the peak absolute magnitude M-I = -19.65 +/- 0.19 on JD = 245 6218.1 +/- 1.8. After maximum, the light curve declines for about 25 d with a rate of 4 mag (100 d)(-1). The symmetric I-band peak resembles that of canonical Type Ib/c supernovae (SNe), whereas SNe Ibn usually exhibit asymmetric and narrower early-time light curves. Since 25 d past maximum, the light curve flattens with a decline rate slower than that of the Co-56-Fe-56 decay, although at very late phases it steepens to approach that rate. However, other observables suggest that the match with the Co-56 decay rate is a mere coincidence, and the radioactive decay is not the main mechanism powering the light curve of OGLE-2012-SN-006. An early-time spectrum is dominated by a blue continuum, with only a marginal evidence for the presence of He I lines marking this SN type. This spectrum shows broad absorptions bluewards than 5000 angstrom, likely O II lines, which are similar to spectral features observed in superluminous SNe at early epochs. The object has been spectroscopically monitored by PESSTO from 90 to 180 d after peak, and these spectra show the typical features observed in a number of SN 2006jc-like events, including a blue spectral energy distribution and prominent and narrow (v(FWHM) approximate to 1900 km s(-1)) He I emission lines. This suggests that the ejecta are interacting with He-rich circumstellar material. The detection of broad (10(4) km s(-1)) O I and Ca II features likely produced in the SN ejecta (including the [OI] lambda lambda 6300,6364 doublet in the latest spectra) lends support to the interpretation of OGLE-2012-SN-006 as a core-collapse event.
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    Microlensing Constraints on the Mass of Single Stars from HST Astrometric Measurements
    (2017) Kains, N.; Calamida, A.; Sahu, K.; Casertano, S.; Anderson, J.; Udalski, A.; Zoccali, Manuela; Bond, H.; Albrow, M.; Bond, I.; Brown,T.; Dominik, M.; Fryer, C.; Livio, M.; Mao, S.; Rejkuba, M.
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    Millimagnitude photometry for transiting extrasolar planetary candidates V. Follow-up of 30 OGLE transits. New candidates
    (EDP SCIENCES S A, 2010) Pietrukowicz, P.; Minniti, D.; Diaz, R. F.; Fernandez, J. M.; Zoccali, M.; Gieren, W.; Pietrzynski, G.; Ruiz, M. T.; Udalski, A.; Szeifert, T.; Hempel, M.
    Aims. We used VLT/VIMOS images in the V band to obtain light curves of the extrasolar planetary transits OGLE-TR-111 and OGLE-TR-113 and the candidate planetary transits: OGLE-TR-82, OGLE-TR-86, OGLE-TR-91, OGLE-TR-106, OGLE-TR-109, OGLE-TR-110, OGLE-TR-159, OGLE-TR-167, OGLE-TR-170, OGLE-TR-171.
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    MOA-2011-BLG-262Lb : A sub-earth-mass moon orbiting a gas giant primary or a high velocity planetary system in the galactic bulge
    (2014) Bennett, D.P.; Batista, V.; Bond, I.A.; Bennett, C.S.; Suzuki, D.; Beaulieu, J.P.; Udalski, A.; Donatowicz, J.; Dekany, Istvan; Minniti, D.
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    OGLE-2014-BLG-1186 : gravitational microlensing providing evidence for a planet orbiting the foreground star or for a close binary source?
    (2019) Dominik, M.; Bachelet, E.; Bozza, V.; Street, R.A.; Han, C.; Hundertmark, M.; Udalski, A.; Bramich, D.M; Alsubai, K.A.; Rabus, Markus; Novati, S.C.; Ciceri, S.; D'Ago, G.; Jaimes, R.F.; Haugbolle, T.; Hinse, T.C.; Horne, K.; Jorgensen, U.G.; Juncher, D.; Kains, N.; Korhonen, H.
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    OGLE-2015-BLG-0479LA,B. : BINARY. GRAVITATIONAL. MICROLENS. CHARACTERIZED. by SIMULTANEOUS. GROUND-BASED. and SPACE-BASED. OBSERVATIONS
    (2016) Han, C.; Udalski, A.; Gould, A.; Zhu, WeI.; Street, R. A.; Yee, J. C.; Beichman, C.; Bryden, C.; Novati, S. CalchI.; Rabus, Markus; Carey, S.; Fausnaugh, M.; Gaudi, B.S.; Henderson, Calen B.; Shvartzvald, Y.; Wibking, B.; Szymański, M. K.; Soszyński, I.; Skowron, J.; Mróz, P.; Poleski, R.
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    OGLE-2015-BLG-1649Lb : A Gas Giant Planet around a Low-mass Dwarf
    (2019) Nagakane, M.; Lee, C.H.; Koshimoto, N.; Suzuki, D.; Udalski, A.; Beaulieu, J.P.; Sumi, T.; Bennett, D.P.; Bond, I.A.; D’Ago, Giuseppe
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    OGLE-2016-BLG-1190Lb: The First Spitzer Bulge Planet Lies Near the Planet/Brown-dwarf Boundary
    (2017) Ryu, Y.-H.; Yee, J. C.; Udalski, A.; Bond, I. A.; Shvartzvald, Y.; Zang, W.; Figuera Jaimes, R.; Jørgensen, U. G.; Zhu, W.; Rabus, Markus
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    OGLE-2017-BLG-0329L : a microlensing binary characterized with dramatically enhanced precision using data from space-based observations
    (2018) Han, C.; Calchi Novati, S.; Udalski, A.; Lee, C.U.; Gould, A.; Bozza, V.; Mróz, P.; Pietrukowicz, Pawel; Skowron, J.; Rabus, Markus
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    OGLE-2017-BLG-0406 : Spitzer Microlens Parallax Reveals Saturn-mass Planet Orbiting M-dwarf Host in the Inner Galactic Disk
    (2020) Hirao, Y.; Bennett, D. P.; Ryu, Y. H.; Koshimoto, N.; Udalski, A.; Yee, J. C.; Sumi, T.; Bond, I. A.; Shvartzvald, Y.; Rabus, Markus; Abe, F.; Barry, R. K.; Bhattacharya, A.; Donachie, M.; Fukui, A.; Itow, Y.; Kondo, I.; Alex Li, M. C.; Matsubara, Y.; Matsuo, T.; Miyazaki, S.; Muraki, Y.; Nagakane, M.; Ranc, C.; Rattenbury, N. J.; Suematsu, H.; Shibai, H.; Suzuki, D.; Tristram, P. J.; Yonehara, A.; Skowron, J.; Poleski, R.; Mróz, P.; Szymański, M. K.; Soszyński, I.; Kozłowski, S.; Pietrukowicz, Pawel; Ulaczyk, K.; Rybicki, K.; Iwanek, P. D.; Albrow, M.; Chung, S. J.; Gould, A.; Han, C.; Hwang, K. H.; Jung, Y. K.; Shin, I. G.; Zang, W.; Cha, S. M.; Kim, D. J.
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    OGLE-TR-211 -: a new transiting inflated hot Jupiter from the OGLE survey and ESO LP666 spectroscopic follow-up program
    (2008) Udalski, A.; Pont, F.; Naef, D.; Melo, C.; Bouchy, F.; Santos, N. C.; Moutou, C.; Diaz, R. F.; Gieren, W.; Gillon, M.; Hoyer, S.; Mayor, M.; Mazeh, T.; Minniti, D.; Pietrzynski, G.; Queloz, D.; Ramirez, S.; Ruiz, M. T.; Shporer, A.; Tamuz, O.; Udry, S.; Zoccali, M.; Kubiak, M.; Szymanski, M. K.; Soszynski, I.; Szewczyk, O.; Ulaczyk, K.; Wyrzykowski, L.
    We present results of the photometric campaign for planetary and low-luminosity object transits conducted by the OGLE survey in the 2005 season (Campaign #5). About twenty of the most promising candidates discovered in these data were subsequently verified spectroscopically with the VLT/FLAMES spectrograph.
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    PATHWAY TO THE GALACTIC DISTRIBUTION OF PLANETS: COMBINED SPITZER AND GROUND-BASED MICROLENS PARALLAX MEASUREMENTS OF 21 SINGLE-LENS EVENTS
    (2015) Novati, S. Calchi; Gould, A.; Udalski, A.; Menzies, J. W.; Bond, I. A.; Shvartzvald, Y.; Street, R. A.; Hundertmark, M.; Beichman, C. A.; Yee, J. C.; Carey, S.; Poleski, R.; Skowron, J.; Kozlowski, S.; Mroz, P.; Pietrukowicz, P.; Pietrzynski, G.; Szymanski, M. K.; Soszynski, I.; Ulaczyk, K.; Wyrzykowski, L.; Albrow, M.; Beaulieu, J. P.; Caldwell, J. A. R.; Cassan, A.; Coutures, C.; Danielski, C.; Prester, D. Dominis; Donatowicz, J.; Loncaric, K.; McDougall, A.; Morales, J. C.; Ranc, C.; Zhu, W.; Abe, F.; Barry, R. K.; Bennett, D. P.; Bhattacharya, A.; Fukunaga, D.; Inayama, K.; Koshimoto, N.; Namba, S.; Sumi, T.; Suzuki, D.; Tristram, P. J.; Wakiyama, Y.; Yonehara, A.; Maoz, D.; Kaspi, S.; Friedmann, M.; Bachelet, E.; Jaimes, R. Figuera; Bramich, D. M.; Tsapras, Y.; Horne, K.; Snodgrass, C.; Wambsganss, J.; Steele, I. A.; Kains, N.; Bozza, V.; Dominik, M.; Jorgensen, U. G.; Alsubai, K. A.; Ciceri, S.; D'Ago, G.; Haugbolle, T.; Hessman, F. V.; Hinse, T. C.; Juncher, D.; Korhonen, H.; Mancini, L.; Popovas, A.; Rabus, M.; Rahvar, S.; Scarpetta, G.; Schmidt, R. W.; Skottfelt, J.; Southworth, J.; Starkey, D.; Surdej, J.; Wertz, O.; Zarucki, M.; Gaudi, B. S.; Pogge, R. W.; De Poy, D. L.
    We present microlens parallax measurements for 21 (apparently) isolated lenses observed toward the Galactic bulge that were imaged simultaneously from Earth and Spitzer, which was similar to 1 AU west of Earth in projection. We combine these measurements with a kinematic model of the Galaxy to derive distance estimates for each lens, with error bars that are small compared to the Sun's galactocentric distance. The ensemble therefore yields a well-defined cumulative distribution of lens distances. In principle, it is possible to compare this distribution against a set of planets detected in the same experiment in order to measure the Galactic distribution of planets. Since these Spitzer observations yielded only one planet, this is not yet possible in practice. However, it will become possible as larger samples are accumulated.
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    Photometric and spectroscopic evolution of the interacting transient AT 2016jbu(Gaia16cfr)
    (2022) Brennan, S. J.; Fraser, M.; Johansson, J.; Pastorello, A.; Kotak, R.; Stevance, H. F.; Chen, T-W; Eldridge, J. J.; Bose, S.; Brown, P. J.; Callis, E.; Cartier, R.; Dennefeld, M.; Dong, Subo; Duffy, P.; Elias-Rosa, N.; Hosseinzadeh, G.; Hsiao, E.; Kuncarayakti, H.; Martin-Carrillo, A.; Monard, B.; Nyholm, A.; Pignata, G.; Sand, D.; Shappee, B. J.; Smartt, S. J.; Tucker, B. E.; Wyrzykowski, L.; Abbot, H.; Benetti, S.; Bento, J.; Blondin, S.; Chen, Ping; Delgado, A.; Galbany, L.; Gromadzki, M.; Gutierrez, C. P.; Hanlon, L.; Harrison, D. L.; Hiramatsu, D.; Hodgkin, S. T.; Holoien, T. W-S; Howell, D. A.; Inserra, C.; Kankare, E.; Kozlowski, S.; Muller-Bravo, T. E.; Maguire, K.; McCully, C.; Meintjes, P.; Morrell, N.; Nicholl, M.; O'Neill, D.; Pietrukowicz, P.; Poleski, R.; Prieto, J. L.; Rau, A.; Reichart, D. E.; Schweyer, T.; Shahbandeh, M.; Skowron, J.; Sollerman, J.; Soszynski, I; Stritzinger, M. D.; Szymanski, M.; Tartaglia, L.; Udalski, A.; Ulaczyk, K.; Young, D. R.; van Leeuwen, M.; van Soelen, B.
    We present the results from a high-cadence, multiwavelength observation campaign of AT 2016jbu (aka Gaia16cfr), an interacting transient. This data set complements the current literature by adding higher cadence as well as extended coverage of the light-curve evolution and late-time spectroscopic evolution. Photometric coverage reveals that AT 2016jbu underwent significant photometric variability followed by two luminous events, the latter of which reached an absolute magnitude of M-V similar to-18.5 mag. This is similar to the transient SN 2009ip whose nature is still debated. Spectra are dominated by narrow emission lines and show a blue continuum during the peak of the second event. AT 2016jbu shows signatures of a complex, non-homogeneous circumstellar material (CSM). We see slowly evolving asymmetric hydrogen line profiles, with velocities of 500 km s(-)(1) seen in narrow emission features from a slow-moving CSM, and up to 10 000 km s(-1) seen in broad absorption from some high-velocity material. Late-time spectra (similar to+1 yr) show a lack of forbidden emission lines expected from a core-collapse supernova and are dominated by strong emission from H, He I, and Ca II. Strong asymmetric emission features, a bumpy light curve, and continually evolving spectra suggest an inhibit nebular phase. We compare the evolution of H alpha among SN 2009ip-like transients and find possible evidence for orientation angle effects. The light-curve evolution of AT 2016jbu suggests similar, but not identical, circumstellar environments to other SN 2009ip-like transients.
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    Precision measurement of a brown dwarf mass in a binary system in the microlensing event OGLE-2019-BLG-0033/MOA-2019-BLG-035
    (2022) Herald, A.; Udalski, A.; Bozza, V.; Rota, P.; Bond, I. A.; Yee, J. C.; Sajadian, S.; Mroz, P.; Poleski, R.; Skowron, J.; Szymanski, M. K.; Soszynski, I.; Pietrukowicz, P.; Kozlowski, S.; Ulaczyk, K.; Rybicki, K. A.; Iwanek, P.; Wrona, M.; Gromadzki, M.; Abe, F.; Barry, R.; Bennett, D. P.; Bhattacharya, A.; Fukui, A.; Fujii, H.; Hirao, Y.; Itow, Y.; Kirikawa, R.; Kondo, I.; Koshimoto, N.; Matsubara, Y.; Matsumoto, S.; Miyazaki, S.; Muraki, Y.; Olmschenk, G.; Ranc, C.; Okamura, A.; Rattenbury, N. J.; Satoh, Y.; Sumi, T.; Suzuki, D.; Silva, S. Ishitani; Toda, T.; Tristram, P. J.; Vandorou, A.; Yama, H.; Beichman, C. A.; Bryden, G.; Novati, S. Calchi; Carey, S.; Gaudi, B. S.; Gould, A.; Henderson, C. B.; Johnson, S.; Shvartzvald, Y.; Zhu, W.; Dominik, M.; Hundertmark, M.; Jorgensen, U. G.; Longa-Pena, P.; Skottfelt, J.; Tregloan-Reed, J.; Bach-Moller, N.; Burgdorf, M.; D'Ago, G.; Haikala, L.; Hitchcock, J.; Khalouei, E.; Peixinho, N.; Rahvar, S.; Snodgrass, C.; Southworth, J.; Spyratos, P.; Zang, W.; Yang, H.; Mao, S.; Bachelet, E.; Maoz, D.; Street, R. A.; Tsapras, Y.; Christie, G. W.; Cooper, T.; de Almeida, L.; do Nascimento, J. -D., Jr.; Green, J.; Han, C.; Hennerley, S.; Marmont, A.; McCormick, J.; Monard, L. A. G.; Natusch, T.; Pogge, R.
    Context. Brown dwarfs are transition objects between stars and planets that are still poorly understood, for which several competing mechanisms have been proposed to describe their formation. Mass measurements are generally difficult to carry out for isolated objects as well as for brown dwarfs orbiting low-mass stars, which are often too faint for a spectroscopic follow-up.
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    Progenitor, environment, and modelling of the interacting transient AT 2016jbu (Gaia16cfr)
    (2022) Brennan, S. J.; Fraser, M.; Johansson, J.; Pastorello, A.; Kotak, R.; Stevance, H. F.; Chen, T-W; Eldridge, J. J.; Bose, S.; Brown, P. J.; Callis, E.; Cartier, R.; Dennefeld, M.; Dong, Subo; Duffy, P.; Elias-Rosa, N.; Hosseinzadeh, G.; Hsiao, E.; Kuncarayakti, H.; Martin-Carrillo, A.; Monard, B.; Pignata, G.; Sand, D.; Shappee, B. J.; Smartt, S. J.; Tucker, B. E.; Wyrzykowski, L.; Abbot, H.; Benetti, S.; Bento, J.; Blondin, S.; Chen, Ping; Delgado, A.; Galbany, L.; Gromadzki, M.; Gutierrez, C. P.; Hanlon, L.; Harrison, D. L.; Hiramatsu, D.; Hodgkin, S. T.; Holoien, T. W-S; Howell, D. A.; Inserra, C.; Kankare, E.; Kozlowski, S.; Muller-Bravo, T. E.; Maguire, K.; McCully, C.; Meintjes, P.; Morrell, N.; Nicholl, M.; O'Neill, D.; Pietrukowicz, P.; Poleski, R.; Prieto, J. L.; Rau, A.; Reichart, D. E.; Schweyer, T.; Shahbandeh, M.; Skowron, J.; Sollerman, J.; Soszynski, I; Stritzinger, M. D.; Szymanski, M.; Tartaglia, L.; Udalski, A.; Ulaczyk, K.; Young, D. R.; van Leeuwen, M.; van Soelen, B.
    We present the bolometric light curve, identification and analysis of the progenitor candidate, and preliminary modelling of AT 2016jbu (Gaia16cfr). We find a progenitor consistent with a similar to 22-25 M-circle dot yellow hypergiant surrounded by a dusty circumstellar shell, in agreement with what has been previously reported. We see evidence for significant photometric variability in the progenitor, as well as strong H alpha emission consistent with pre-existing circumstellar material. The age of the environment, as well as the resolved stellar population surrounding AT 2016jbu, supports a progenitor age of >10 Myr, consistent with a progenitor mass of similar to 22 M-circle dot. A joint analysis of the velocity evolution of AT 2016jbu and the photospheric radius inferred from the bolometric light curve shows the transient is consistent with two successive outbursts/explosions. The first outburst ejected material with velocity similar to 650 km s(-1), while the second, more energetic event ejected material at similar to 4500 km s(-1). Whether the latter is the core collapse of the progenitor remains uncertain. We place a limit on the ejected Ni-56 mass of <0.016 M-circle dot. Using the Binary Population And Spectral Synthesis (BPASS) code, we explore a wide range of possible progenitor systems and find that the majority of these are in binaries, some of which are undergoing mass transfer or common-envelope evolution immediately prior to explosion. Finally, we use the SuperNova Explosion Code (SNEC) to demonstrate that the low-energy explosions within some of these binary systems, together with sufficient circumstellar material, can reproduce the overall morphology of the light curve of AT 2016jbu.