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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
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To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

5843 results found.

  1. LIGO/Virgo G275404: iPTF Optical Transient Candidates
  2. LIGO/Virgo G275404: Nearby galaxy observations by J-GEM collaboration
  3. LIGO/Virgo G275697: INTEGRAL search for a prompt gamma-ray counterpart
  4. LIGO/Virgo G275404: SVOM/Mini-GWAC: Observations of initial skymap
  5. IPN Triangulation of GRB 170222A (short/hard)
  6. LIGO/Virgo G274296: J-GEM optical/NIR follow-up observations
  7. LIGO/Virgo G274296: iPTF Optical Transient Candidates
  8. LIGO/Virgo G274296: Asiago 1.82m Optical Observations
  9. LIGO/Virgo G274296: PESSTO classification of 9 Pan-STARRS transients
  10. LIGO/Virgo G274296: Pan-STARRS imaging and discovery of 70 transients
  11. LIGO/Virgo G274296: Global MASTER Net SN bright detection during GW error box inspection
  12. LIGO/Virgo G274296: Observations of initial skymap by project Mini-GWAC of SVOM
  13. LIGO/Virgo G274296: REM optical/NIR observations
  14. GRB 170214A: GROND detection in all bands
  15. GRB 170208B: SMARTS optical/IR observations
  16. IPN Triangulation of GRB 170209A
  17. Correction to GCN 20640: GRB 170208B: GROND observations
  18. Fermi Trigger 508295323: MASTER-OAFA possible OT detection
  19. GRB 170208B: GROND observations
  20. GRB 170208B: Swift detection of a burst
  21. LIGO/Virgo G270580: Gemini-South Spectroscopic Classification of Optical Transients
  22. GRB 170205A: Swift detection of a burst with an optical counterpart
  23. GRB 170202A: SQUEAN Observation (2nd night)
  24. GRB 170202A: Swift detection of a burst with an optical afterglow
  25. LIGO/Virgo G270580: Las Cumbres Observatory Follow-up Observations
  26. LIGO/Virgo G270580: Swift/UVOT follow-up of PS17yt
  27. LIGO/Virgo G270580: Pan-STARRS coverage and 124 optical transients
  28. LIGO/Virgo G270580: A third optical transient from CNEOST
  29. LIGO/Virgo G270580: INTEGRAL search of temporally coincident prompt hard X-ray
  30. LIGO/Virgo G270580: Swift-XRT sources
  31. LIGO/Virgo G268556: Global MASTER Net 21 OTs detection
  32. LIGO/Virgo G270580: Observations of initial skymap by Project Mini-GWAC of SVOM
  33. GRB 170113A: Swift detection of a burst with an optical counterpart
  34. LIGO/Virgo G268556: Additional GROWTH follow up observation of iPTF Optical Transient Candidates
  35. LIGO/Virgo G268556: Liverpool Telescope Spectroscopy of iPTF17bv and iPTF17ck
  36. GRB 170109A: POLAR Observation
  37. LIGO/Virgo G268556: NOWT of EWE, Xinglong 0.6/0.9m, Xuyi 1m optical upper limits of ATLAS17aeu and a reminder of GCN 20394
  38. LIGO/Virgo G268556: Pan-STARRS1 observations and summary of transient sources
  39. LIGO/Virgo G268556: GWAC_F60B (60cm) follow-up two events of EWE001 and EWE002
  40. LIGO/Virgo G268556: Continued iPTF Observations and Additional Optical Transient Candidates
  41. LIGO/Virgo G268556: iPTF Optical Transient Candidates
  42. LIGO/Virgo G268556/GW170104: Asiago Observations
  43. LIGO/Virgo G268556: ATLAS17aeu - an unusual transient within the skymap
  44. LIGO/Virgo G268556/GW170104: Global MASTER Net observations and first OT detection
  45. LIGO/Virgo G268556: ATLAS imaging of the skymap
  46. LIGO/Virgo G211117 / GW151226: LOFAR follow-up
  47. LIGO/Virgo G268556: observation regions by Project Mini-GWAC of SVOM
  48. GRB 161220A: Swift detection of a burst
  49. GRB 161214B: Swift detection of a burst
  50. MASTER: Optical Blazar Flare Detection during Fermi trigger 502272781 inspection
  51. GRB 161202A: MITSuME Okayama upper limits
  52. GRB 161202A: Swift detection of a burst
  53. GRB 161129A: MITSuME Okayama Ks-band Observation
  54. GRB 161129A: MITSuME Okayama Optical Observation
  55. GRB 161123A: MAXI/GSC detection
  56. GRB 161117B: Swift detection of a burst
  57. GRB 161117A: Swift detection of a burst with an optical counterpart
  58. GRB 161108A: continued TSHAO optical observations
  59. GRB 161109A: Lomonosov BDRG gamma ray discovery
  60. GRB 161109A: Fermi-LAT detection
  61. GRB 161108A: Swift detection of a burst
  62. Fermi LAT Gamma-ray Observations of IceCube-161103
  63. IceCube-161103: Konus-Wind upper limits
  64. GRB 161105A: Swift detection of a burst
  65. IceCube-161103: Swift-XRT observations
  66. GRB 161104A: Swift detection of a short burst
  67. INTEGRAL SPI-ACS and IBIS/Veto observation of IceCube-161103
  68. IceCube-161103: MASTER follow-up observations
  69. HAWC follow up of IceCube-161103
  70. IceCube-161103: IceCube observation of a very-high-energy neutrino
  71. GRB 161023A: LCOGT-FTS optical observations
  72. Swift Trigger 718919 is not an astrophysical event.
  73. Swift Trigger 718766 is not an astrophysical event.
  74. GRB161017A optical R band observations with SARA-RM
  75. GRB 161017A: Lomonosov Gamma Ray and MASTER Optical prompt observations
  76. GRB 161017A: Swift/UVOT Detection
  77. GRB 161017A: Swift detection of a burst with a bright optical afterglow
  78. GRB161017.74 MASTER-Net OT detection
  79. GRB 161014A: Swift detection of a burst
  80. GRB 161007A: NOT optical observations
  81. GRB 161007A: Swift detection of a burst
  82. GRB 160925A: Kottamia R-band observation
  83. GRB 161004B: Swift detection of a burst
  84. GRB 161001A: MASTER-OAFA and MASTER-SAAO early optical observations
  85. GRB 161001A: GROND afterglow candidate
  86. GRB 160927A: NOT optical observations
  87. GRB 160927A: GROND Observations
  88. GRB 160925A/MASTER optical transient: Mondy optical observations
  89. GRB 160925A: MITSuME Akeno Optical Observations
  90. GRB 160925A: Bassano Bresciano Photometry of MASTER optical transient
  91. GRB 160925A: Optical spectroscopy of MASTER optical transient
  92. GRB 160925A / Fermi 496473540: Global MASTER Net OT discovery
  93. GRB 160917A: Mondy afterglow confirmation
  94. GRB 160910A: TSHAO optical observations
  95. GRB 160917A: RATIR Optical and NIR Observations
  96. GRB 160917A: Mondy optical observations
  97. GRB 160910A: Maidanak optical observations
  98. GRB 160912A: RATIR Optical and NIR Observations
  99. GRB 160912A: Mondy optical observations
  100. GRB 160910A: Mondy optical observations

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