IGR J17091-3624

IGR J17091 was discovered by ESA's INTEGRAL satellite in April 2003.{{cite web|url=http://www.astronomerstelegram.org/?read=149|title=IGR J17091-3624|website=astronomerstelegram.org|author=Erik Kuulkers |access-date=January 17, 2013|date=April 19, 2003}}

IGR J17091 is a stellar mass black hole with a mass between 3 and 10 {{solar mass}}. It is a binary system in which a star orbits the black hole.{{cite web|url= http://chandra.harvard.edu/press/12_releases/press_022112.html|title=Chandra Finds Fastest Winds from Stellar Black Hole|publisher=NASA|author=Ashley King|display-authors=etal|access-date=September 27, 2012|date=February 21, 2012}} Its small size may make it a candidate for the smallest black hole discovered.{{cite web|url=http://www.space.com/15941-strangest-black-holes-universe-countdown.html|title=Strangest Black Holes in the Universe, pg 9|work= Space.com|author=Charles Q. Choi|access-date=September 27, 2012|date=August 24, 2012}} However, as of 2017 its mass was described as "unknown".{{cite journal|last1= Xu|first1= Y.|last2= García|first2= J.A.|last3= Fürst|first3= F.|last4= Harrison|first4= F.A.|last5= Walton|first5= D.J.|last6= Tomsick|first6= J.A.|last7= Bachetti|first7= M.|last8= King|first8= A.L.|last9= Madsen|first9= K.K.|last10= Miller|first10= J.M.|last11= Grinberg|first11= V.|title= Spectral and Timing Properties of IGR J17091–3624 in the Rising Hard State During Its 2016 Outburst |journal= The Astrophysical Journal|volume= 851|issue= 2|year= 2017|pages= 103|doi= 10.3847/1538-4357/aa9ab4|arxiv= 1711.04421|bibcode= 2017ApJ...851..103X|s2cid= 119414510|doi-access= free}}

Observations by the Chandra X-ray Observatory in 2011 discovered that it produces the fastest winds ever coming from an accretion disk at 3,218,688 km/h (20 million mph) making it about 3% of the speed of light. This is 10 times faster than the next-highest-measured wind speed. According to Ashley King from the University of Michigan "Contrary to the popular perception of black holes pulling in all of the material that gets close, we estimate up to 95 percent of the matter in the disk around IGR J17091 is expelled by the wind."{{cite web|url= http://chandra.harvard.edu/press/12_releases/press_022112.html|title=Chandra Finds Fastest Winds from Stellar Black Hole|publisher=NASA|author=Ashley King|display-authors=etal|access-date=September 27, 2012|date=February 21, 2012}}

IGR J17091 also exhibits peculiar X-ray variability patterns or "heartbeats" which are small, quasi-periodic, outbursts repeated over a 5- to 70-second timescale.{{cite journal |last1=Rao |first1=Anjali |last2=Vadawale |first2=S. V. |date=12 September 2012 |title=Why is IGR J17091–3624 so faint? |journal=The Astrophysical Journal |volume=757 |issue=1 |page=1 |arxiv=1209.2506|bibcode = 2012ApJ...757L..12R |doi = 10.1088/2041-8205/757/1/L12 |s2cid=118636206 }} Similar variability has only been observed in the black hole GRS 1915+105; however, IGR J17091's outbursts are 20 times fainter.{{cite journal |last1=Rao |first1=Anjali |last2=Vadawale |first2=S. V. |date=12 September 2012 |title=Why is IGR J17091–3624 so faint? |journal=The Astrophysical Journal |volume=757 |issue=1 |page=2 |arxiv=1209.2506|bibcode = 2012ApJ...757L..12R |doi = 10.1088/2041-8205/757/1/L12 |s2cid=118636206 }}

• List of black holes
• Micro black hole
• Hawking radiation

{{reflist|60em}}

• [http://chandra.harvard.edu/press/12_releases/press_022112.html NASA's Chandra Finds Fastest Winds From Stellar-Mass Black Hole] - Chandra.Harvard.edu
• [http://www.nasa.gov/topics/universe/features/black-hole-heartbeat.html NASA's RXTE Detects 'Heartbeat' of Smallest Black Hole Candidate] - NASA.gov, with animation

{{Stars of Scorpius}}

Category:Scorpius

Category:Stellar black holes

Category:Astronomical X-ray sources

Category:Binary stars