Improving the prospects for detecting extrasolar planets in gravitational microlensing events in 2002

Abstract

Gravitational microlensing events of high magnification have been shown to be promising targets for detecting extrasolar planets. However, only a few events of high magnification have been found using conventional survey techniques. Here we demonstrate that high‐magnification events can be readily found in microlensing surveys using a strategy that combines high‐frequency sampling of target fields with on‐line difference imaging analysis. We present 10 microlensing events with peak magnifications greater than 40 that were detected in real‐time towards the Galactic bulge during 2001 by the Microlensing Observations in Astrophysics (MOA) project. We show that Earth‐mass planets can be detected in future events such as these through intensive follow‐up observations around the event peaks. We report this result with urgency as a similar number of such events are expected in 2002.

The Extreme Microlensing Event Ogle-2007-BLG-224: Terrestrial Parallax Observation of a Thick-Disk Brown Dwarf

“…= −28:45:36) was announced as a probable microlensing event by the OGLE collaboration (Udalski 2003) on 2007 May 9 and independently by the MOA collaboration (Bond et al 2002) on May 12 as MOA-2007-BLG-163. At discovery, it was already recognized to be quite short, Einstein timescale t E ∼ 7 days, and was consistent with peaking at high magnification, although with very low probability of doing so.…”

Radio observations of the planetary nebula around the OH/IR star OH 354.88-0.54 (V1018 Sco)

“…represents a quotient map obtained directly from SuperCOS-MOS data for the PN by dividing the Hα pixel data by the corresponding data from the short-red (SR) exposure. However, it also involves the use of theBond et al (2002) technique of variable point spread function (PSF) matching between the two images prior to13 cm Figure 3. 13-cm ATCA continuum image of OH 354.88-0.54 as for Fig.…”

Difference imaging photometry of blended gravitational microlensing events with a numerical kernel

“…Over the last 15 years, gravitational microlensing (Einstein 1936) has been observed routinely and used in the study ⋆ E-mail:Michael.Albrow@canterbury.ac.nz (MDA) † http://www.beatricetinsleyinstitute.org/ of dark baryonic matter (Alcock et al 1993;Aubourg et al 1993) and stellar atmospheres (Albrow et al 1999(Albrow et al , 2001aFields et al 2003;Cassan et al 2004), and in the search for extrasolar planets (Albrow et al 2000(Albrow et al , 2001cGaudi et al 2002;Bond et al 2004;Udalski et al 2005;Beaulieu et al 2006;Dong et al 2008;Gaudi et al 2008). The PLANET collaboration (Albrow et al 1998) operates a number of 1-m class telescopes distributed around the Southern Hemisphere and performs round-the-clock CCD photometry of microlensing events that have been discovered and alerted in real time by the OGLE (Udalski et al 1994;Udalski 2003) and MOA (Bond et al 2002) microlensing surveys.…”