OGLE2-TR-L9b

{{Infobox planet

| name = OGLE2-TR-L9b

| image = Star OGLE2-TR-L9 and planet.png

| caption = Artist impression of OGLE2-TR-L9b and its star

| discoverer = Meta de Hoon
Remco van der Burg
Francis Vuijsje

| discovered = December 2, 2008

| discovery_method = Transit

| apsis = astron

| period = 2.4855335 ± 0.0000007 d
59.6528 h

| star = OGLE2-TR-L9

| mean_radius = {{val|1.958|0.174|0.111}} {{jupiter radius|link=y}}

| mass = 4.5 ± 1.5 {{Jupiter mass|link=y}}

}}

OGLE2-TR-L9b is an extrasolar planet discovered by three undergraduate students from Leiden University, Netherlands.

The planet is about 4.5 times as massive as Jupiter and is the first discovered planet orbiting a fast-rotating hot star.{{cite journal

| author=Snellen

| title=OGLE2-TR-L9b: an exoplanet transiting a rapidly rotating F3 star

| journal=Astronomy and Astrophysics

| date=2009

| volume=497

| issue=2| pages=545–550

| doi=10.1051/0004-6361/200810917

| last2=Koppenhoefer

| first2=J.

| last3=Van Der Burg

| first3=R. F. J.

| last4=Dreizler

| first4=S.

| last5=Greiner

| first5=J.

| last6=De Hoon

| first6=M. D. J.

| last7=Husser

| first7=T. O.

| last8=Krühler

| first8=T.

| last9=Saglia

| first9=R. P.

| bibcode=2009A&A...497..545S|last10 = Vuijsje| first10=F. N.

|arxiv = 0812.0599 | s2cid=15639369

| url=http://goedoc.uni-goettingen.de/goescholar/bitstream/handle/1/9693/aa10917-08.pdf?sequence=2

}}

Initially discovered while testing a method for investigating light fluctuations in the OGLE database, the planet's existence was later confirmed by follow-up observations from the ESO's Very Large Telescope in Chile.