THE SPITZER MICROLENSING PROGRAM AS A PROBE FOR GLOBULAR CLUSTER PLANETS: ANALYSIS OF OGLE-2015-BLG-0448

• Published in: The Astrophysical journal 2016-05, Vol.823 (1), p.63-63
• Main Authors: Poleski, Rados aw, Zhu, Wei, Christie, Grant W., Udalski, Andrzej, Gould, Andrew, Bachelet, Etienne, Skottfelt, Jesper, Novati, Sebastiano Calchi, Szyma ski, M. K., Soszy ski, I., Pietrzy ski, G., Wyrzykowski, ., Ulaczyk, K., Pietrukowicz, P., Koz owski, Szymon, Skowron, J., Mróz, 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., Jørgensen, 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., Essen, C. von, Wang, Y.-B., Wertz, O.
• Format: Article
• Language: English
• Subjects: ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; Aérospatiale, astronomie & astrophysique; Clusters; DETECTION; DISTRIBUTION; Globular clusters; globular clusters: individual (NGC6558); GRAVITATIONAL LENSES; gravitational lensing: micro; Lenses; Microlenses; OGLE-2015-BLG-0448; Parallax; PHOTOMETRY; Physical, chemical, mathematical & earth Sciences; Physique, chimie, mathématiques & sciences de la terre; Planetary probes; PLANETS; planets and satellites: detection; PROPER MOTION; proper motions; SATELLITES; Sciences of the Universe; Space science, astronomy & astrophysics
• ISSN: 0004-637X; 1538-4357; 1538-4357
• DOI: 10.3847/0004-637X/823/1/63

ABSTRACT 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 ( 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.