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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').
Advanced Search

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.

Advanced Search Examples (click to copy):

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

23604 results found.

  1. Konus-Wind observation of GRB 061222A
  2. GRB 061210: Swift/XRT Astrometry Correction
  3. GRB 061222B: TAROT La Silla observatory early optical observations
  4. GRB 061218: TAROT La Silla observatory early optical observations
  5. GRB 061222B, Swift-BAT refined analysis
  6. GRB 061222B: Observation with the KANATA 1.5m telescope
  7. GRB 061222A: Observation with the KANATA 1.5m telescope
  8. GRB 061222B: BOOTES-IR optical observations
  9. GRB 061222A, Swift-BAT refined analysis
  10. GRB 061222B: TAROT La Silla observatory afterglow observation
  11. GRB 061222B: TAROT La Silla observatory optical observations
  12. GRB 061222B: Swift detection of a burst
  13. GRB 061222: Swift detection of a burst
  14. GRB 061217: Astrometry-Corrected XRT Position
  15. GRB 061217: Confirmation of host candidate
  16. GRB 061217: Extended object in the revised XRT error circle
  17. GRB 061217, Candidate host galaxy
  18. GRB 061210: Possible Host Galaxy (S2-G2) Keck Spectrum
  19. GRB 061201: Magellan Redshift of nearby Abell cluster
  20. GRB 061218: TAROT La Silla observatory optical observations
  21. GRB 061217: TAROT Calern observatory optical observations
  22. GRB 061218, Swift-BAT refined analysis
  23. GRB 061218, SMARTS optical/IR observations
  24. Swift triggers (#251863) on a possible burst
  25. GRB061217: Swift/UVOT refined analysis.
  26. GRB 061217: optical observations at Calar Alto
  27. GRB 061217, Swift-BAT refined analysis
  28. GRB 061217: Magellan Observations
  29. GRB 061217: Swift detection of a short hard burst
  30. Swift-BAT Trigger 250908 is a Cosmic Ray Shower event
  31. GRB 061210 : Faulkes North Telescope optical limit
  32. GRB 061214(?): Swift detection of a possible burst
  33. GRB 061210: Suzaku WAM observation of the prompt emission
  34. GRB 061213: MASTER-VWF-Kislovodsk optical candidate
  35. GRB 061213: MASTER-VWF-Kislovodsk observations
  36. GRB 061126: a GRB detected off-axis by INTEGRAL
  37. GRB 061202: Suzaku WAM observation of the prompt emission
  38. GRB 061210, Swift-BAT refined analysis of the SHB
  39. GRB 061210: Swift-BAT detection of a short burst
  40. Optical Afterglow observations of GRB 061126
  41. GRB061126: optical observations
  42. GRB 060926: MASTER: discovery of the optical flare
  43. GRB 061201: SOAR Confirmation of Candidate Afterglow
  44. GRB 061202: Swift XRT refined analysis
  45. Konus-Wind observation of GRB 061201
  46. GRB 061202, Swift-BAT refined analysis
  47. GRB 061202: Swift detection of a burst
  48. GRB 061201: Swift XRT Team refined analysis
  49. GRB 061201, Swift-BAT refined analysis of the SHB
  50. GRB 061201: Swift detection of a short hard burst
  51. GRB 061126: Possible Jet Break
  52. Swift XRT on-board boresight update
  53. GRB 061126: Early Super-LOTIS Observations
  54. RHESSI Spectrum of GRB061126
  55. GRB061126: Optical afterglow observations from MIRO
  56. GRB061126: Optical afterglow observations from MIRO
  57. GRB 061126 : SDSS Pre-Burst Observations
  58. GRB 061126: Swift-XRT refined analysis
  59. GRB 061126, Swift-BAT refined analysis
  60. GRB 061126: SARA Observations
  61. GRB 061126: Faulkes Telescope North Optical Observations
  62. GRB 061126: XRT position
  63. GRB 061126: Swift detection of a burst
  64. GRB 061121: Ep,i - Eiso correlation
  65. Konus-Wind observation of GRB 061122
  66. RHESSI Spectrum of GRB061121
  67. Konus-Wind and Konus-A observations of GRB 061121
  68. INTEGRAL results on GRB 061122
  69. Swift-BAT trigger 239987 is not a GRB
  70. GRB 061122A: a long GRB detected by INTEGRAL
  71. GRB 061121, Swift-BAT refined analysis
  72. GRB061121, optical observation
  73. GRB 061121: Optical observation at the KANATA 1.5m telescope
  74. GRB 061121: Faulkes Telescope North Optical Observation
  75. GRB 061121: Swift detection of a bright burst with an optical counterpart
  76. Swift-BAT triggers 238544 and 238546 are not GRBs
  77. GRB 061110A - VLT tentative redshift
  78. GRB 061110B, Swift-BAT refined analysis
  79. GRB 061110B : Liverpool Telescope Optical Afterglow Detection
  80. GRB 061110B: Swift-UVOT Initial Observation
  81. GRB 061110A, Swift-BAT refined analysis
  82. GRB 061110B: TAROT Calern observatory optical observations
  83. GRB 061110B: Swift detection of a burst
  84. GRB 061110 : Optical afterglow candidate
  85. GRB 061110: Swift detection of a burst
  86. Swift-BAT Trigger 237821 is a Cosmic Ray Shower event
  87. GRB 061109: TAROT Calern observatory optical observations
  88. GRB 061109: Swift detection of a possible burst
  89. GRB061028: MAGIC telescope GeV observation
  90. GRB 061027: TAROT La Silla observatory optical observations
  91. GRB 061007: Third Epoch ATCA Radio Observations
  92. Swift-BAT Trigger 236481 is a Cosmic Ray Shower event
  93. GRB 061028: Optical R passband observations
  94. GRB 061102B: Swift detection of a possible burst
  95. GRB 061102, Swift-BAT refined analysis
  96. GRB 061102: Swift detection of a burst
  97. GRB 061028: Futher P200 Observations
  98. GRB 061028: P200 Observations
  99. GRB 061028: SARA upper limit
  100. GRB 061028: z band imaging

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