3C 454.3

{{Short description|Blazar and strong gamma ray source}}

{{Quasar

| name = 3C 454.3

| image = 267641main allsky labeled HI.jpg

| caption= Fermi-LAT gamma-ray image, including 3C 454.3

| epoch = J2000

| ra = {{RA|22|53|57.7}}{{Cite simbad |title=3C 454.3|access-date=25 June 2014}}

| dec = {{DEC|+16|08|53.6}}

| constellation name = Pegasus

| z = 0.859001 ± 0.000170

| type = Blazar/Quasar

| dist_ly = 7.7 Gly

| appmag_v = 16.1

| size_v =

| mass=886 ± 187 × 10⁶

| luminosity=10¹²

}}

3C 454.3 is a blazar (a type of quasar with a jet oriented toward Earth) located away from the galactic plane. It is one of the brightest gamma ray sources in the sky,{{cite web|last1=Atkinson|first1=Nancy|title=Top Ten Gamma Ray Sources From the Fermi Telescope|url=http://www.universetoday.com/26831/top-ten-gamma-ray-sources-from-the-fermi-telescope/|website=Universe Today|date=11 March 2009 |access-date=25 June 2014}} and is one of the most luminous astronomical object ever observed, with a maximum absolute magnitude of -31.4.{{cite web|title=The most luminous quasar state ever observed|url=http://www.caha.es/the-most-luminous-quasar-state-ever-observed.html|publisher=Calar Alto Observatory|access-date=5 January 2015|archive-url=https://web.archive.org/web/20150407050257/http://www.caha.es/the-most-luminous-quasar-state-ever-observed.html|archive-date=2015-04-07|url-status=dead}} It has the brightest blazar gamma ray flare recorded, twice as bright as the Vela Pulsar in the Milky Way galaxy. It also flares at radio and visible wavelengths – in red light, the blazar brightened by more than 2.5 times to magnitude 13.7 – and it is very bright at high radio frequencies.{{Cite web |title=NASA - Fermi Sees Brightest-Ever Blazar Flare |url=http://www.nasa.gov/mission_pages/GLAST/news/brightest-blazar.html |website=NASA |access-date=31 May 2015}}

It appears in Pegasus, near Alpha Pegasi (Markab). It has been known to occasionally outburst, brightening to a peak apparent magnitude of 13.4 in June 2014.{{cite web|last1=King|first1=Bob|title=Observing Alert: Distant Blazar 3C 454.3 in Outburst, Visible in Amateur Telescopes|url=http://www.universetoday.com/112744/observing-alert-distant-blazar-3c-454-3-in-outburst-visible-in-amateur-telescopes/|website=Universe Today|date=24 June 2014 |access-date=25 June 2014}}{{cite web|title=Light Curve Generator for 3C 454.3|url=http://www.aavso.org/lcg/plot?auid=000-BDC-612&starname=3C+454.3&lastdays=30&start=06/15/2014&stop=&obscode=&obscode_symbol=2&obstotals=yes&calendar=calendar&forcetics=&grid=on&visual=on&uband=on&bband=on&v=on&pointsize=1&width=800&height=450&mag1=&mag2=&mean=&vmean=|publisher=American Association of Variable Star Observers|access-date=16 July 2014|archive-date=5 March 2016|archive-url=https://web.archive.org/web/20160305021947/http://www.aavso.org/lcg/plot?auid=000-BDC-612&starname=3C+454.3&lastdays=30&start=06%2F15%2F2014&stop=&obscode=&obscode_symbol=2&obstotals=yes&calendar=calendar&forcetics=&grid=on&visual=on&uband=on&bband=on&v=on&pointsize=1&width=800&height=450&mag1=&mag2=&mean=&vmean=|url-status=dead}}