Optical Gravitational Lensing Experiment

The Optical Gravitational Lensing Experiment (OGLE) is a Polish astronomical project based at the University of Warsaw that runs a long-term variability sky survey (1992–present). The main goals are the detection and classification of variable stars (pulsating and eclipsing), discovery of microlensing events, dwarf novae, and studies of the structure of the Galaxy and the Magellanic Clouds. Since the project began in 1992, it has discovered a multitude of extrasolar planets, together with the first planet discovered using the transit method (OGLE-TR-56b) and gravitational microlensing. The project has been led by professor Andrzej Udalski since its inception.

Description

File:OGLE-IV-BLG-fields-overview.png

The main targets of the experiment are the Magellanic Clouds and the Galactic Bulge, because of the large number of intervening stars that can be used for microlensing during a stellar transit. Most of the observations have been made at the Las Campanas Observatory in Chile. Cooperating institutions include Princeton University and the Carnegie Institution.

The project is now in its fourth phase. The first phase, OGLE-I (1992–1995), used the {{convert|1.0|m|adj=on}} Swope telescope and a single-chip CCD sensor. For OGLE-II (1996–2000), a {{convert|1.3|m|adj=on}} telescope dedicated to the project (the Warsaw telescope) was constructed at Las Campanas Observatory. It was equipped with a single 2048×2048 pixel sensor with a field of view 0.237 degrees wide.{{cite journal|title=Optical Gravitational Lensing Experiment. OGLE-2 – the Second Phase of the OGLE Project |first1=A. |last1=Udalski |first2=M. |last2=Kubiak |first3=M. |last3=Szymański |arxiv=astro-ph/9710091 |citeseerx=10.1.1.315.9784 |bibcode=1997AcA....47..319U |journal=Acta Astronomica |volume=47 |issue=3 |pages=319–344 |year=1997 |url=http://acta.astrouw.edu.pl/Vol47/n3/pap_47_3_1.pdf}}

OGLE-III (2001–2009) expanded the camera to a mosaic of eight 2048×4096 pixel CCDs, and was able to search for gravitational microlensing events and transiting planets in four fields: the Galactic Bulge, the constellation Carina,{{cite journal|last1=Udalski |first1=Andrzej |title=The Optical Gravitational Lensing Experiment. Real Time Data Analysis Systems in the OGLE-III Survey |year=2003 |journal=Acta Astronomica |volume=53 |issue=4 |pages=291–306 |bibcode=2003AcA....53..291U |arxiv=astro-ph/0401123 |citeseerx=10.1.1.316.4693 |url=http://acta.astrouw.edu.pl/Vol53/n4/pap_53_4_1.pdf}} and toward both Magellanic Clouds. As a byproduct of the constant monitoring of hundreds of millions of stars, the largest catalogs of variable stars were constructed, and the first exoplanets discovered using the microlensing technique were detected.

In 2010, following engineering work in 2009, the fourth and current phase, OGLE-IV, was started using a 32-chip mosaic CCD camera which fills the Warsaw telescope's 1.5° field of view.{{cite journal|title=OGLE-IV: Fourth Phase of the Optical Gravitational Lensing Experiment |first1=A. |last1=Udalski |first2=M. K. |last2=Szymański |first3=G. |last3=Szymański |journal=Acta Astronomica |volume=65 |issue=1 |pages=1–38 |year=2015 |arxiv=1504.05966 |bibcode=2015AcA....65....1U |url=http://acta.astrouw.edu.pl/Vol65/n1/pdf/pap_65_1_1.pdf}} The main goal for this phase is to increase the number of planetary detections using microlensing, enabled by the new camera.

Recently the OGLE team, in cooperation with scientists mostly from the US, New Zealand and Japan, proved that small, Earth-like planets can exist at a significant distance from stars around which they revolve despite there being other stars near them.{{Cite web|url=https://www.fnp.org.pl/laureaci-fnp-odkryli-zimna-ziemie/ |title=Laureaci FNP odkryli zimną Ziemię|date=7 July 2014 |language=pl |trans-title=FNP laureates have discovered a cold Earth |access-date=13 November 2020 |publisher=Foundation for Polish Science (FNP)}}{{Cite journal|doi=10.1126/science.1251527 |pmid=24994642 |title=A terrestrial planet in a ~1-AU orbit around one member of a ~15-AU binary |journal=Science |volume=345 |issue=6192 |pages=46–49 |date=4 July 2014 |last1=Gould |first1=A. |display-authors=etal |arxiv=1407.1115 |bibcode=2014Sci...345...46G|s2cid=206555598 }}

In January 2022 in collaboration with Microlensing Observations in Astrophysics (MOA) they reported in a preprint the first rogue black hole.{{cite journal |last1=Sahu |first1=Kailash C. |last2=Anderson |first2=Jay |last3=Casertano |first3=Stefano |last4=Bond |first4=Howard E. |last5=Udalski |first5=Andrzej |last6=Dominik |first6=Martin |last7=Calamida |first7=Annalisa |last8=Bellini |first8=Andrea |last9=Brown |first9=Thomas M. |last10=Rejkuba |first10=Marina |last11=Bajaj |first11=Varun |date=2022-05-25 |title=An Isolated Stellar-mass Black Hole Detected through Astrometric Microlensing |journal=The Astrophysical Journal |volume=933 |issue=1 |page=83 |doi=10.3847/1538-4357/ac739e |arxiv=2201.13296|bibcode=2022ApJ...933...83S |s2cid=246430448 |doi-access=free }}{{cite journal |last1=Lam |first1=Casey Y. |last2=Lu |first2=Jessica R. |last3=Udalski |first3=Andrzej |last4=Bond |first4=Ian |last5=Bennett |first5=David P. |last6=Skowron |first6=Jan |last7=Mroz |first7=Przemek |last8=Poleski |first8=Radek |last9=Sumi |first9=Takahiro |last10=Szymanski |first10=Michal K. |last11=Kozlowski |first11=Szymon |date=2022-05-31 |title=An Isolated Mass-gap Black Hole or Neutron Star Detected with Astrometric Microlensing |journal=The Astrophysical Journal Letters |volume=933 |issue=1 |pages=L23 |doi=10.3847/2041-8213/ac7442 |arxiv=2202.01903|bibcode=2022ApJ...933L..23L |s2cid=246608178 |doi-access=free }}{{Cite web |last=Gianopoulos |first=Andrea |date=2022-06-07 |title=Hubble Determines Mass of Isolated Black Hole Roaming Milky Way |url=http://www.nasa.gov/feature/goddard/2022/hubble-determines-mass-of-isolated-black-hole-roaming-our-milky-way-galaxy |access-date=2022-06-12 |website=NASA}}{{Cite web |last=O'Callaghan |first=Jonathan |title=Astronomers Find First Ever Rogue Black Hole Adrift in the Milky Way |url=https://www.scientificamerican.com/article/astronomers-find-first-ever-rogue-black-hole-adrift-in-the-milky-way/ |access-date=2022-02-08 |website=Scientific American |language=en}} While there have been other candidates{{Cite journal|last1=Bennett|first1=D. P.|last2=Becker|first2=A. C.|last3=Quinn|first3=J. L.|last4=Tomaney|first4=A. B.|last5=Alcock|first5=C.|last6=Allsman|first6=R. A.|last7=Alves|first7=D. R.|last8=Axelrod|first8=T. S.|last9=Calitz|first9=J. J.|last10=Cook|first10=K. H.|last11=Drake|first11=A. J.|date=2002-11-10|title=Gravitational Microlensing Events Due to Stellar-Mass Black Holes|url=https://iopscience.iop.org/article/10.1086/342225|journal=The Astrophysical Journal|language=en|volume=579|issue=2|pages=639–659|doi=10.1086/342225|arxiv=astro-ph/0109467|bibcode=2002ApJ...579..639B|s2cid=44193135|issn=0004-637X}} this is the most solid detection so far as their technique allowed to measure not only the amplification of light but also its deflection by the BH from the microlensing data.

Planets discovered

At least seventeen planets have so far been discovered by the OGLE project. Eight of the planets were discovered by the transit method and six by the gravitational microlensing method.

Planets are shown in the order of discovery. Planets in multiple-planet systems are highlighted in yellow.

class="toccolours sortable" border=1 cellspacing=0 cellpadding=2 align=center style="text-align:center; border-collapse:collapse; margin-left: 0; margin-right: auto;"
bgcolor="#a0b0ff" ! Star ! Constellation ! Right ascension ! Declination ! App. mag. ! Distance (ly) ! Spectral type ! Planet ! Mass (M_J) ! Radius (R_J) ! Orbital period (d) ! a (AU) ! ecc. ! incl. (°) ! Discovery year
OGLE-TR-10	Sagittarius	{{RA\|17\|51\|28}}	{{DEC\|−29\|52\|34}}	15.78	5000	G2V \| OGLE-TR-10 b	0.63	1.26	3.10129	0.04162	0	84.5	2002
OGLE-TR-111	Carina	{{RA\|10\|53\|01}}	{{DEC\|−61\|24\|20}}	16.96	5000	G \| OGLE-TR-111 b	0.53	1.0	4.01610	0.047	0	88.1	2002
OGLE-TR-132	Carina	{{RA\|10\|50\|34}}	{{DEC\|−61\|57\|25}}	15.72	7110	F \| OGLE-TR-132 b	1.14	1.18	1.689868	0.0306	0	85	2003
OGLE-TR-56	Sagittarius	{{RA\|17\|56\|35}}	{{DEC\|−29\|32\|21}}	16.56	4892	G \| OGLE-TR-56 b	1.29	1.30	1.211909	0.0225	0	78.8	2003
OGLE-TR-113	Carina	{{RA\|10\|52\|24}}	{{DEC\|−61\|26\|48}}	16.08	1800	K \| OGLE-TR-113 b	1.32	1.09	1.4324757	0.0229	0	89.4	2004
OGLE-2003-BLG-235L /MOA-2003-BLG-53L	Sagittarius	{{RA\|18\|05\|16}}	{{DEC\|−28\|53\|42}}		19000	K \| OGLE-2003-BLG-235Lb \| 2.6			4.3			2004
OGLE-2005-BLG-071L	Scorpius	{{RA\|17\|50\|09}}	{{DEC\|−34\|40\|23}}	19.5	9500	M \| OGLE-2005-BLG-071Lb	3.5		3600	3.6			2005
OGLE-2005-BLG-169L	Sagittarius	{{RA\|18\|06\|05}}	{{DEC\|–30\|43\|57}}	19.4	8800	M? \| OGLE-2005-BLG-169Lb	0.041	0.345					2006
OGLE-2005-BLG-390L	Sagittarius	{{RA\|17\|54\|19}}	{{DEC
30\|22\|38}}		21500	M? \| OGLE-2005-BLG-390Lb	0.018						2006
OGLE-TR-211	Carina	{{RA\|10\|40\|15}}	{{DEC\|−62\|27\|20}}		5300	F \| OGLE-TR-211 b	1.03	1.36	3.67724	0.051	0	≥87.2	2007
OGLE-TR-182	Carina	{{RA\|11\|09\|19}}	{{DEC\|−61\|05\|43}}	16.84	12700	G \| OGLE-TR-182 b	1.01	1.13	3.9791	0.051	0	85.7	2007
OGLE2-TR-L9	Carina	{{RA\|11\|07\|55}}	{{DEC\|−61\|08\|46}}		2935	F3 \| OGLE2-TR-L9 b	4.5	1.61	2.4855335	0.0308			2008
bgcolor="#ffffb0" \| rowspan=2\| OGLE-2006-BLG-109L	rowspan=2\| Sagittarius	rowspan=2\| {{RA\|17\|52\|35}}	rowspan=2\| {{DEC\|−30\|05\|16}}	rowspan=2\|	rowspan=2\| 4900	rowspan=2\| M0V? \| OGLE-2006-BLG-109Lb	0.71		1825	2.3			2008
bgcolor="#ffffb0" \| OGLE-2006-BLG-109Lc	0.27		5100	4.8	0.11	59	2008
bgcolor="#ffffb0" \| rowspan=2\| OGLE-2012-BLG-0026L	rowspan=2\|	rowspan=2\| {{RA\|17\|34\|19}}	rowspan=2\| {{DEC\|−27\|08\|34}}	rowspan=2\|	rowspan=2\| 4080	rowspan=2\| \| OGLE-2012-BLG-0026Lb	0.11			3.82			2012
bgcolor="#ffffb0" \| OGLE-2012-BLG-0026Lc	0.68			4.63			2012
OGLE-2011-BLG-0251		{{RA\|17\|38\|14}}	{{DEC\|−27\|08\|10}}		8232	M \| OGLE-2011-BLG-0251 b	0.53			2.72 or 1.5			2013
OGLE-2007-BLG-349(AB)					8000	\| OGLE-2007-BLG-349(AB)b	0.25			2.9 \|		2016
OGLE-2016-BLG-1190L	Sagittarius	{{RA\|17\|58\|53}}	{{DEC\|−27\|36\|49}}		22000	G \| OGLE-2016-BLG-1190Lb	13.38		1223.6	2.17	0.42	41.2	2017
OGLE-2016-BLG-1195L						\| OGLE-2016-BLG-1195Lb	0.0045 \|					2017
OGLE-2013-BLG-0132L \| \| \| \| \|13000 \| \|OGLE-2013-BLG-0132Lb \|0.29 \| \| \| \| \| \|2017
OGLE-2013-BLG-1721L \| \| \| \| \|21000 \| \|OGLE-2013-BLG-1721Lb \|0.64 \| \| \|2.6 \| \| \|2017
OGLE-2016-BLG-0263L \| \| \| \| \|21000 \| \|OGLE-2016-BLG-0263Lb \|4.10 \| \| \|5.4 \| \| \|2017
OGLE-2018-BLG-0799L					2900 \| \| OGLE-2018-BLG-0799Lb	0.22 \|		1.75 \|		2018
N/A \| \| \| \| \| \| \|OGLE-2019-BLG-0551b \|0.0242 \| \| \| \| \| \|2020
OGLE-2019-BLG-0960L \| \| \| \| \| \| \|OGLE-2019-BLG-0960Lb \|0.0071 \| \| \| \| \| \|2021

File:Artist's Concept of Exoplanet OGLE-2005-BLG-390L b.jpg discovered by the OGLE Team]]

Notes: For events detected by the gravitational microlensing method, year stands for OGLE season, BLG means that an event detected is in the Galactic BuLGe, and the following 3-digit number is an ordinal number of microlensing event in that season. For events detected by the transit method TR stands for TRansit and the following 3-digit number is an ordinal number of transit event.

Gallery

OGLE_telescope_from_the_road.jpg|View on the OGLE telescope (in the foreground on the left) and Swope Telescope (in the background above the center)

OGLE_telescope_sign.jpg|Sign to the OGLE telescope. Twin 6.5-meter Magellan Telescopes are seen in the background

OGLE_telescope_inside_the_dome1.jpg|OGLE telescope inside the dome

OGLE_telescope_inside_the_dome2.jpg|Telescope with the attached OGLE-IV camera

References

{{Reflist|refs=

{{cite journal | title=A Transiting Extrasolar Giant Planet around the Star OGLE-TR-10 | last1=Konacki | first1=Maciej | last2=Torres | first2=Guillermo | last3=Sasselov | first3=Dimitar D. | last4=Jha | first4=Saurabh | display-authors=1 | journal=The Astrophysical Journal | volume=624 | issue=1 | pages=372–377 | date=2005 | arxiv=astro-ph/0412400 | bibcode=2005ApJ...624..372K | doi=10.1086/429127 | s2cid=119347135 }}

{{cite journal| title= The Optical Gravitational Lensing Experiment. Search for Planetary and Low-Luminosity Object Transits in the Galactic Disk. Results of 2001 Campaign | url=http://acta.astrouw.edu.pl/Vol52/n1/a_52_1_1.html | last1=Udalski | first1=A. | last2=Paczynski | first2=B. | last3=Żebruń | first3=K. | last4=Szymański | first4=M. | last5=Kubiak | first5=M. | last6=Soszyński | first6=I. | last7=Szewczyk | first7=O. | last8=Wyrzykowski | first8=L. | last9=Pietrzyński | first9=G. | display-authors=1 | journal=Acta Astronomica | volume=52 | issue=1 | pages=1–37 | date=2002 | arxiv=astro-ph/0202320 | bibcode=2002AcA....52....1U }}

}}

External links

[http://ogle.astrouw.edu.pl/ OGLE Homepage in Warsaw, Poland]
OGLE-IV [http://www.astrouw.edu.pl/~jskowron/ogle4-sky/ sky coverage maps]
Detailed [http://ogle.astrouw.edu.pl/sky/ogle4-fields.html OGLE-IV fields] diagrams

Category:Astronomical surveys

Category:Experiments for dark matter search

Category:Gravitational lensing

Category:Telescopes

Category:Exoplanet search projects

Category:Astronomy projects