QSO B0839+187

{{Short description|Quasar in the constellation Cancer}}

{{Quasar

| name = QSO B0839+187

| image =

| epoch = J2000

| ra = {{RA|08|42|05.0942}}

| dec = {{DEC|+18|35|40.991}}

| constellation name = Cancer

| z = 1.27[http://simbad.u-strasbg.fr/simbad/sim-id?protocol=html&Ident=QSO+J0842%2B1835&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id Simbad]

| type = Rad

| dist_ly = 8.4 billion light-years
(Light travel time){{cite web

|title=NASA/IPAC Extragalactic Database

|work=Results for 0839+1846

|url=http://nedwww.ipac.caltech.edu/cgi-bin/nph-objsearch?objname=0839%2B1846&extend=no

|access-date=2010-04-20 }}

| appmag_v = 16.36

| size_v =

| notes =

| names = LEDA 2825583, PKS J0842+1835, PKS 0839+187, 2MASS J08420509+1835411, QSO B0839+1846

}}

QSO B0839+187 (PKS 0839+187) is a quasar that was used for a VLBI experiment conducted by Edward Fomalont and Sergei Kopeikin in September 2002. They claimed to measure the speed of gravity, but this is disputed.{{cite journal |first1=Ed |last1=Fomalont |first2=Sergei |last2=Kopeikin |name-list-style=amp |year=2003 |title=The measurement of the light deflection from Jupiter: Experimental results |journal=The Astrophysical Journal |volume=598 |issue=1 |pages=704–711 |doi=10.1086/378785 |bibcode=2003ApJ...598..704F |arxiv=astro-ph/0302294|s2cid=14002701 }}{{cite journal |first=Hideki |last=Asada |year=2002 |title=Light cone effect and the Shapiro time delay |journal=The Astrophysical Journal Letters |volume=574 |issue=1 |pages=L69–L70 |doi=10.1086/342369 |bibcode=2002ApJ...574L..69A |arxiv=astro-ph/0206266|s2cid=14589086 }}{{cite journal |author1=Stuart Samuel |title=On the Speed of Gravity and the v/c Corrections to the Shapiro Time Delay |journal=Physical Review Letters |year=2003 |volume=90 |issue=23 |page= 231101 |doi=10.1103/PhysRevLett.90.231101 |pmid=12857246 |arxiv=astro-ph/0304006|bibcode=2003PhRvL..90w1101S |s2cid=15905017 }}