31:
406:(VLBI). Subsequent, more detailed VLBI observations demonstrated the expected (parity reversed) magnification of the image B jet with respect to image A jet. The difference between the large-scale radio images is attributed to the special geometry needed for gravitational lensing, which is satisfied by the quasar but not by all of the extended jet emission seen by the VLA near image A.
401:
which increases the gravitational deflection and can explain the observed distance between the images. Finally, a team led by Marc V. Gorenstein observed essentially identical relativistic jets on very small scales from both A and B in 1983 using
440:
approximately three Earth masses in size within the lensing galaxy. This conjecture cannot be proven because the chance alignment that led to its discovery will never happen again. If it could be confirmed, however, it would make it the
554:
Kundic, T.; Turner, E.L.; Colley, W.N.; Gott, III; Rhoads, J.E. (1997). "A robust determination of the time delay in 0957+561A,B and a measurement of the global value of Hubble's constant".
952:
416:
30 years of observation made it clear that image A of the quasar reaches earth about 14 months earlier than the corresponding image B, resulting in a difference of path length of 1.1
409:
Slight spectral differences between quasar A and quasar B can be explained by different densities of the intergalactic medium in the light paths, resulting in differing
356:
and visible light spectrum were very similar to each other. They published their suggestion of "the possibility that they are two images of the same object formed by a
469:
asserted that "this quasar appears to be dynamically dominated by a magnetic field internally anchored to its central, rotating supermassive compact object" (
247:
The Twin Quasar is a single quasar whose appearance is distorted by the gravity of another galaxy much closer to Earth along the same line of sight. This
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of 17, with the A component having 16.7 and the B component having 16.5. There is a 417 ± 3-day time lag between the two images.
363:
The Twin Quasar was one of the first directly observable effects of gravitational lensing, which was described in 1936 by
822:"VLBI Observations of the Gravitational Lens System 0957+561: Structure and Relative Magnification of the A and B Images"
386:
emerging from quasar A with no corresponding equivalent in quasar B. Furthermore, the distance between the two images, 6
35:
The Twin Quasar QSO 0957+561, which lies 8.7 billion light-years from Earth, is seen right in the center of this picture.
120:
442:
390:, was too great to have been produced by the gravitational effect of the galaxy G1, a galaxy identified near quasar B.
174:
403:
352:
in
Arizona, United States. The team noticed that the two quasars were unusually close to each other, and that their
497:
371:, though in that 1936 paper he also predicted "Of course, there is no hope of observing this phenomenon directly."
309:
909:
980:
349:
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259:. The single quasar thus appears as two separate images, separated by 6 arcseconds. Both images have an
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discovered an anomalous fluctuation in one image's light curve, which they speculated was caused by a
730:
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458:
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746:"The double quasar Q0957 + 561 A, B – A gravitational lens image formed by a galaxy at Z = 0.39"
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946:
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833:
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757:
688:
679:(1936). "Lens-like action of a star by the deviation of light in the gravitational field".
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The quasars QSO 0957+561A/B were discovered in early 1979 by an Anglo-American team around
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970:
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943: – CCD image based on 45-min total exposure – March 2007.
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that appears as two images, a result from gravitational lensing caused by the galaxy
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Gorenstein, M. V.; et al. (1984). "The milli-arcsecond images of Q0957 + 561".
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Young, P.; Gunn, J. E.; Oke, J. B.; Westphal, J. A. & Kristian, J. (1980).
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348:, Robert Carswell and Ray Weyman, with the aid of the 2.1 m Telescope at
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53:
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336:) lying within a cluster of galaxies that also contributed to the lensing.
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Critics identified a difference in appearance between the two quasars in
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suggested that the accreting object at the heart of Q0957+561 is not a
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177: 2518326, A: USNO-A2 1425-7427021 B:USNO-A2 1425-7427023
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620:"0957 + 561 A, B: twin quasistellar objects or gravitational lens?"
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30:
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183:
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285:). The lensing galaxy with apparent dimension of 0.42×0.22
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Walsh, D.; Carswell, R. F.; Weymann, R. J. (31 May 1979).
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and collaborators discovered that galaxy G1 is part of a
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images. In mid-1979, a team led by David
Roberts at the
239:
that is located directly between Earth and the quasar.
223:), was discovered in 1979 and was the first identified
553:
161:
Twin Quasar, Double Quasar, Twin QSO,
743:
617:
541:
Bill Keel's WWW Gallery-Active
Galaxies and Quasars|
449:
Candidate magnetospheric eternally collapsing object
543:https://pages.astronomy.ua.edu/keel/agn/q0957.html
461:, as is generally believed for all quasars, but a
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931:Q0957+561: Die historisch erste Linse mit Quasar
887:
312:(NED) list several other names for this system.
169:0957+561, SBS 0957+561, TXS 0957+561,
320:The lensing galaxy, YGKOW G1 (sometimes called
289:lies almost in line with the B image, lying 1
382:(VLA) near Socorro, New Mexico, discovered a
277:), while the lensing galaxy lies at redshift
227:double quasar, not to be confused with the
607:Nomenclature of Celestial Objects (Result I)
293:off. The quasar lies 10 arcminutes north of
467:Harvard-Smithsonian Center for Astrophysics
430:Harvard-Smithsonian Center for Astrophysics
819:
784:
463:magnetospheric eternally collapsing object
845:
769:
723:"Science: The Mysterious Celestial Twins"
567:
85:+55° 53′ 56.5″
890:"Do alien worlds throng faraway galaxy?"
675:
146:
132:
986:Astronomical objects discovered in 1979
820:Gorenstein, M. V.; et al. (1988).
963:
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255:by the nearby galaxy, as described by
910:"Research Sheds New Light on Quasars"
251:effect is a result of the warping of
229:first detection of light deflection
13:
423:
304:. The astronomical data services
14:
997:
924:
404:Very Long Baseline Interferometry
888:Govert Schilling (6 July 1996).
729:. 1 October 1979. Archived from
498:Hypothetical astronomical object
310:NASA/IPAC Extragalactic Database
29:
902:
881:
861:Müller, Andreas (August 2007).
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813:
976:Gravitationally lensed quasars
778:
737:
715:
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522:ESA/Hubble Picture of the Week
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350:Kitt Peak National Observatory
1:
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367:as a consequence of his 1916
16:Gravitationally lensed quasar
369:general theory of relativity
7:
701:10.1126/science.84.2188.506
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10:
1002:
339:
935:The University of Cologne
443:most distant known planet
242:
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131:Apparent dimensions
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78:
64:
52:
40:
28:
24:The Twin Quasar Q0957+561
23:
266:The Twin Quasar lies at
863:"Quasare im Doppelpack"
465:. Schild's team at the
459:supermassive black hole
315:
225:gravitationally lensed
981:Gravitational lensing
826:Astrophysical Journal
787:Astrophysical Journal
750:Astrophysical Journal
445:, 4 billion ly away.
281:= 0.355 (3.7 billion
249:gravitational lensing
273:= 1.41 (8.7 billion
838:1988ApJ...334...42G
799:1984ApJ...287..538G
762:1980ApJ...241..507Y
733:on 7 November 2012.
693:1936Sci....84..506E
639:1979Natur.279..381W
578:1997ApJ...482...75K
428:In 1996, a team at
933: –
493:Gravitational lens
358:gravitational lens
261:apparent magnitude
257:general relativity
156:Other designations
143:Apparent magnitude
687:(2188): 506–507.
633:(5712): 381–384.
483:Cloverleaf quasar
231:in 1919. It is a
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41:Observation data
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898:. No. 2037.
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677:Einstein, Albert
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569:astro-ph/9610162
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384:relativistic jet
380:Very Large Array
221:QSO 0957+561 A/B
173: 0958+561,
165: 0957+561,
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916:. 26 July 2006.
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518:"Seeing double"
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424:Possible planet
376:radio frequency
365:Albert Einstein
342:
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199:(also known as
188:List of quasars
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110:(2,400,000,000
84:
71:
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66:Right ascension
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5:
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925:External links
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914:SpaceDaily.com
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807:10.1086/162712
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399:galaxy cluster
395:Peter J. Young
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947:Q0957+561 A,B
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867:Astro-Lexikon
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54:Constellation
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957:
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871:. Retrieved
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749:
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731:the original
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562:(1): 75–82.
559:
556:Astrophys. J
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537:
525:. Retrieved
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471:R. E. Schild
455:R. E. Schild
452:
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408:
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346:Dennis Walsh
343:
326:Q0957+561 G1
325:
321:
319:
278:
270:
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220:
216:
213:TXS 0957+561
212:
209:SBS 0957+561
208:
204:
200:
196:
194:
18:
873:17 December
869:(in German)
793:: 538–548.
756:: 507–520.
197:Twin Quasar
137:6" distance
80:Declination
72:10 01 20.99
971:Ursa Major
965:Categories
527:20 January
504:References
411:extinction
388:arcseconds
330:elliptical
302:Ursa Major
287:arcminutes
253:space-time
182:See also:
59:Ursa Major
941:Q0957+561
832:: 42–58.
453:In 2006,
393:In 1980,
297:, in the
291:arcsecond
217:Q0957+561
709:17769014
655:16068158
477:See also
354:redshift
295:NGC 3079
268:redshift
237:YGKOW G1
201:Twin QSO
102:Distance
92:Redshift
834:Bibcode
795:Bibcode
758:Bibcode
689:Bibcode
681:Science
663:2142707
635:Bibcode
594:1249658
574:Bibcode
432:led by
340:History
334:type cD
953:Simbad
707:
661:
653:
627:Nature
592:
438:planet
306:SIMBAD
243:Quasar
233:quasar
184:Quasar
145:
47:J2000)
659:S2CID
623:(PDF)
590:S2CID
564:arXiv
96:1.413
45:Epoch
875:2023
727:Time
705:PMID
651:PMID
529:2014
316:Lens
308:and
195:The
151:16.7
121:Type
842:doi
830:334
803:doi
791:287
766:doi
754:241
697:doi
643:doi
631:279
582:doi
560:482
473:).
360:".
324:or
219:or
175:PGC
163:QSO
147:(V)
133:(V)
126:Rad
967::
912:.
892:.
865:.
840:.
828:.
824:.
801:.
789:.
764:.
752:.
748:.
725:.
703:.
695:.
685:84
683:.
657:.
649:.
641:.
629:.
625:.
588:.
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572:.
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520:.
420:.
418:ly
413:.
322:G1
283:ly
275:ly
215:,
211:,
207:,
203:,
186:,
171:8C
112:pc
108:ly
949:.
937:.
877:.
850:.
844::
836::
809:.
805::
797::
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768::
760::
711:.
699::
691::
665:.
645::
637::
596:.
584::
576::
566::
531:.
332:(
279:z
271:z
167:Q
114:)
43:(
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