OGLE-2018-BLG-1185b: A Low-mass Microlensing Planet Orbiting a Low-mass Dwarf

Kondo, Iona; Yee, Jennifer C.; Bennett, D. P.; Sumi, T.; Koshimoto, Naoki; Bond, I. A.; Gould, Andrew; Udalski, A.; Shvartzvald, Yossi; Jung, Youn Kil; Zang, Weicheng; Bozza, V.; Bachelet, E.; Hundertmark, M.; Rattenbury, N. J.; Abe, F.; Barry, Richard; Bhattacharya, Aparna; Donachie, M.; Fukui, A.; Fujii, Hirosane; Hirao, Yuki; Silva, S. Ishitani; Itow, Y.; Kirikawa, Rintaro; Li, M. C. A.; Matsubara, Y.; Miyazaki, Shota; Muraki, Y.; Olmschenk, Greg; Ranc, Clément; Satoh, Yuki; Shoji, Hikaru; Suzuki, D.; Tanaka, Yuzuru; Tristram, P. J.; Yamawaki, Tsubasa; Yonehara, A.; Mróz, P.; Poleski, R.; Skowron, J.; Szymański, M. K.; Soszyński, I.; Kozłowski, S.; Pietrukowicz, P.; Ulaczyk, K.; Rybicki, K.; Iwanek, P.; Wrona, Marcin; Albrow, M. D.; Chung, Sun-Ju; Han, Cheongho; Hwang, Kyu-Ha; Kim, H.-W.; Shin, In-Gu; Cha, Sang-Mok; Kim, D.-J.; Kim, S.-L.; Lee, C.-U.; Lee, D.-J.; Lee, Y.; Park, B.-G.; Pogge, Richard W.; Ryu, Yoon-Hyun; Beichman, Charles; Bryden, G.; Novati, S. Calchi; Carey, Sean; Gaudi, B. Scott; Henderson, Calen B.; Zhu, Wei; Maoz, Dan; Penny, Matthew T.; Dominik, M.; Jørgensen, U. G.; Longa-Peña, Penélope; Peixinho, N.; Sajadian, Sedighe; Skottfelt, J.; Snodgrass, C.; Tregloan-Reed, J.; Burgdorf, M.; Campbell-White, J.; Dib, Sami; Fujii, Yuri I.; Hinse, T. C.; Khalouei, Elahe; Rahvar, S.; Southworth, J.; Tsapras, Y.; Street, R. A.; Bramich, D. M.; Cassan, A.; Horne, K.; Wambsganß, J.; Mao, Shude; Saha, Abhijit

doi:10.3847/1538-3881/ac00ba

“…In other events, source stars pass close to the caustic instead of crossing it, e.g., the left event in Figure 3. Some examples of such events are reported in Han et al (2021); Kondo et al (2021).…”

Section: Statistical Calculationsmentioning

confidence: 95%

Sensitivity to habitable planets in the \textit{Roman} microlensing survey

Sajadian

2021

Preprint

0

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We study the Roman sensitivity to exoplanets in the Habitable Zone (HZ). The Roman efficiency for detecting habitable planets is maximized for three classes of planetary microlensing events with close caustic topologies. (a) The events with the lens distances of D l 7 kpc, the host lens masses of M h 0.6M . By assuming Jupiter-mass planets in the HZs, these events have q 0.001 and d 0.17 (q is their mass ratio and d is the projected planet-host distance on the sky plane normalized to the Einstein radius). The events with primary lenses, M h 0.1M , while their lens systems are either (b) close to the observer with D l 1 kpc or (c) close to the Galactic bulge, D l 7 kpc. For Jupiter-mass planets in the HZs of the primary lenses, the events in these two classes have q 0.01, d 0.04. The events in the class (a) make larger caustics. By simulating planetary microlensing events detectable by Roman, we conclude that the Roman efficiencies for detecting Earth-and Jupiter-mass planets in the Optimistic HZs (OHZs, which is the region between [0.5, 2] AU around a Sun-like star) are 0.01% and 5%, respectively. If we assume that one exoplanet orbits each microlens in microlensing events detectable by Roman ( i.e., ∼ 27000 ), this telescope has the potential to detects 35 exoplanets with the projected planet-host distances in the OHZs with only one having a mass 10M ⊕ . According to the simulation, 27 of these exoplanets are actually in the OHZs.

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“…An interesting system was a scaled 1/2 solar system, with two gazeous planets, of 1/2 the mass of Jupiter and Saturn, with a factor 2 in the major axis of their orbit [11]. It was followed by a number of super-Earth / mini-Neptunes /Neptunes [12][13][14][15][16][17][18][19][20], circum-binary planet [21], a first exomoon candidate system [22], planet in the Galactic Bulge [23][24][25], multiple planet systems [26], Jupiter in the habitable zone [27], massive Jupiter orbiting a M dwarf [28,29] that are not predicted by the core accretion theory [30][31][32]. Microlensing also provided the first detection of a Jupiter orbiting a white dwarf on a wide orbit [33], giving an example of the fate of our solar system once the sun would have go through a planetary nebulae phase in more than 5 Gyrs.…”

Section: A Brief History Of Microlensing Planet Huntmentioning

confidence: 99%

Hunting for Cold Exoplanets via Microlensing

Beaulieu¹

2024

Comptes Rendus. Physique

0

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Microlensing can detect planets at distances ranging from a few hundred parsecs all the way to the Galactic center. The maximum sensitivity is reached for systems that are located half way to the galactic center, with planets orbiting the lens star at a separation of few AUs. It is the only method currently probing exoplanets in the Earth-Saturn mass range beyond the snow line, where the core accretion theory originally predicted that most massive planets would form. Although the number of detected planets is relatively modest (∼ 130 planets to date) compared to that discovered by radial velocity and transit methods, microlensing probes a part of the parameter space (host separation as a function of planet mass), which is mostly not accessible in the medium term to any other technique. Microlensing has discovered the first cold super-Earth, and the first Jupiter planet orbiting a white dwarf. It also detected a number of Earth, Super-Earth, Neptune, Saturn, Jupiter, super-Jupiter orbiting main sequence stars in the mass range 0.08 − 1M ⊙ . It also observed circumbinary planets, Jupiter in the habitable zone, the first exomoon candidate and freefloating planets. It has shown that having a planet is the rule for stars in our galaxy and shown that super-Earth and Neptune are more abundant than smaller mass telluric planets. Ground based microlensing will provide soon the mass function of cold planets down to few Earth Masses. The next phase, is a 450 days survey with the NASA Nancy Grace Roman Space Telescope from 2027. It will detect 3000+ planets and provide the mass function of cold planets down to the mass of Mars. If combined with the European Euclid Space mission, we will be able to probe for free-floating telluric planets and measure their masses.Résumé. La méthode des microlentilles gravitationnelles permet de détecter des planètes à des distances allant de quelques centaines de parsecs jusqu'au centre de notre Galaxie. La sensibilité maximale est atteinte pour les systèmes situés à mi-chemin du centre galactique, avec des planètes orbitant autour de l'étoile lentille à une distance de quelques UA. C'est la seule méthode qui permet actuellement de sonder les exoplanètes dans la gamme de masse Terre-Saturne au-delà de la limite des glaces, là où les scénarios d'accrétion de coeur prédisent que la plupart des planètes massives se formeraient. Bien que le nombre de planètes détectées soit relativement modeste (environ 130 planètes à ce jour) comparé aux méthodes de vitesse radiale et de transit, les microlentilles sondent une partie de l'espace des paramètres (séparation de l'hôte par rapport à la masse de la planète), qui n'est accessible à moyen terme à aucune autre technique. Les microlentilles ont permis de découvrir la première super-Terre froide et la première planète Jupiter en orbite autour d'une naine blanche. Elles ont aussi détecté des Terres, super-Terres, Neptunes, Saturnes, Jupiters, super-Jupiters, naines brunes orbitant autour d'étoiles de la séquence principale dans la gamme de masse 0.08 − 1M ...

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“…Regarding OGLE-2018-BLG-1185, Kondo et al (2021) showed that the blend star, which dominates the light of both the Gaia entry and the OGLE-III catalog star, is separated from the source by 175 mas and is unrelated to the event. Note that they also found that the Gaia proper motion of this blend star (which has a highly unusual value) strongly conflicts with the OGLE-based proper motion (which has a very typical value), and they therefore concluded that the Gaia proper motion was spurious.…”

Section: Role Of Gaia In Planetary Microlensingmentioning

confidence: 99%

Systematic KMTNet Planetary Anomaly Search. VI. Complete Sample of 2018 Sub-prime-field Planets

Jung

¹

,

Zang

²

,

Han

³

et al. 2022

AJ

Self Cite

21

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We complete the analysis of all 2018 sub-prime-field microlensing planets identified by the KMTNet AnomalyFinder. Among the 9 previously unpublished events with clear planetary solutions, 6 are clearly planetary (OGLE-2018-BLG-0298, KMT-2018-BLG-0087, KMT-2018-BLG-0247, KMT-2018-BLG-0030, OGLE-2018-BLG-1119, and KMT-2018-BLG-2602), while the remaining 3 are ambiguous in nature. The above ordering of these events is made to facilitate grouping of their Bayesian estimates: the first two are lower-mass gas giants while the last four are Jovian-class planets; the first three most likely lie in the bulge, the last in the disk, and the remaining two are equally likely to be in either population. More specifically, these six planets have host masses M host = ( 0.69 − 0.30 + 0.34 , 0.10 − 0.05 + 0.14 , 0.29 − 0.14 + 0.28 , 0.51 − 0.31 + 0.43 , 0.48 − 0.28 + 0.35 , 0.66 − 0.36 + 0.42 ) M ⊙ , planet masses M planet = ( 0.14 − 0.06 + 0.07 , 0.23 − 0.12 + 0.32 , 2.11 − 1.04 + 2.09 , 1.45 − 0.88 + 1.23 , 0.91 − 0.52 + 0.66 , 1.15 − 0.63 + 0.73 ) M Jup , and distances D L = ( 6.54 − 1.23 + 0.95 , 7.02 − 1.15 + 1.03 , 6.76 − 1.24 + 0.99 , 6.48 − 1.96 + 1.28 , 5.76 − 2.48 + 1.43 , 4.31 − 1.84 + 1.97 ) kpc . In addition, there are 8 previously published sub-prime-field planets that were selected by the AnomalyFinder algorithm. Together with a companion paper on 2018 prime-field planets, this work lays the basis for comprehensive statistical studies. We carry out two such studies, one on caustic topologies and the other on the role of Gaia data. From the first, as expected, half (17/33) of the 2018 planets likely to enter the mass-ratio analysis have non-caustic-crossing anomalies. However, only 1 of the 5 noncaustic anomalies with planet-host mass ratio q < 10−3 was discovered by eye (compared to 7 of the 12 with q > 10−3), showing the importance of the semiautomated AnomalyFinder search. From the second, we find that Gaia has played a major role in the interpretation of 16% of the sample and a supplementary role in 6%.

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OGLE-2018-BLG-1185b: A Low-mass Microlensing Planet Orbiting a Low-mass Dwarf

Abstract: Kondo et al.

Cited by 12 publications

References 96 publications

Sensitivity to habitable planets in the \textit{Roman} microlensing survey

Sensitivity to habitable planets in the \textit{Roman} microlensing survey

Hunting for Cold Exoplanets via Microlensing

Systematic KMTNet Planetary Anomaly Search. VI. Complete Sample of 2018 Sub-prime-field Planets

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