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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"

21770 results found.

  1. GRB060204B: Swift/UVOT refined analysis
  2. GRB 060204C: optical observations
  3. Swift XRT Observation of GRB 060204C
  4. GRB 060204B: Swift-BAT refined analysis
  5. GRB 060204B: ART early limit
  6. GRB 060204b: Keck/LRIS Afterglow Confirmation
  7. GRB 060204C: Liverpool Telescopes optical limit
  8. GRB 060204C: ROTSE-III Optical Limits
  9. GRB 060204C: Swift-BAT detection of a burst
  10. GRB060204B, optical observation
  11. GRB060204B - SDSS pre-burst observations
  12. GRB 060204B: Swift detection of a burst
  13. GRB 060202: UKIRT/WFCAM K-band and KeckI/LRIS I-band Observation
  14. GRB 060203: RTT150 optical observations
  15. Swift-BAT trigger is GRB 060203
  16. GRB 060203: IR Counterpart
  17. GRB060203: Observations with SARA
  18. GRB 060203: P60 Confirmation of Optical Afterglow
  19. Possible GRB 060203: optical observations at Asiago
  20. GRB 060202: Gemini-N J, H, K_s observations
  21. GRB 060202: Near-IR Observation with UKIRT/WFCAM
  22. GRB 060202: Optical Afterglow Candidate from Keck/LRIS
  23. GRB060202, optical observation
  24. GRB 060202: Swift/UVOT upper limits
  25. GRB 060202: Swift detection of a burst
  26. GRB 060121: Gemini Late-time Observations
  27. GRB 060130: PROMPT Observations
  28. GRB060130: Further R-band imaging
  29. GRB 060130: Swift/XRT observation
  30. GRB060130: Optical imaging
  31. GRB060130: REM infrared observations
  32. GRB 060130, SMARTS optical observations
  33. GRB 060130: FRAM optical observations
  34. GRB 060121: Confirmation of NIR Afterglow
  35. GRB 060123: Swift refined analysis of an unusual GRB
  36. GRB060124, BVRcIc field calibration
  37. GRB060105: refined analysis of the Suzaku observation
  38. GRB 060121: Probable Detection of NIR Afterglow
  39. GRB 060116 HST observations
  40. Konus-Wind observation of GRB 060124
  41. GRB 060124: ART optical limits during the burst
  42. GRB060123: Optical and IR Imaging
  43. GRB 060123: P200 Observations
  44. GRB 060124: R band Observations
  45. GRB 060124 : Optical observation at Xinglong and Kiso
  46. GRB060123: SDSS pre-burst observations
  47. GRB 060123: Swift detection of a very long, faint burst
  48. GRB 060121: OHP optical limits
  49. GRB 060124: TAROT optical limits
  50. GRB060124, optical observation
  51. GRB 060124: Optical Observations at Tautenburg
  52. GRB 060117: Suzaku WAM observation of the prompt emission
  53. GRB 060111B: Suzaku WAM observation of the prompt emission
  54. GRB 060124: Swift-BAT detection of a burst
  55. GRB 060121: Swift/UVOT upper limits
  56. GRB 060121: Liverpool Telescopes optical limits
  57. GRB 060121: Swift XRT refined analysis
  58. Konus-Wind observation of GRB 060121
  59. GRB 060121: I-band Limits
  60. GRB 060121: candidate optical counterpart
  61. GRB 060121: Swift XRT refined position
  62. GRB 060121: Infrared Observations
  63. GRB 060121: optical observations
  64. GRB 060121: Optical imaging
  65. GRB060121 - SDSS pre-burst observations
  66. GRB 060121: A short-hard GRB in a cluster?
  67. HETE Alert 4006: MASTER promt optical limit
  68. GRB 060117: PROMPT Observations
  69. GRB060117 - ATCA 3/6cm radio limits - correction
  70. GRB060117 - ATCA 3/6cm radio limits
  71. Konus-Wind observation of GRB 060117
  72. GRB 060116: UKIRT IR Observations
  73. GRB 060117: Refined analysis of the Swift-BAT burst
  74. GRB 060116: PROMPT Observations
  75. GRB 060117: FRAM optical afterglow candidate
  76. GRB 060117: nearby galaxy
  77. GRB 060116: VLT optical observations
  78. GRB 060115: PROMPT Observations
  79. GRB 060116: IR Candidate Afterglow
  80. GRB 060116: Swift/UVOT upper limits
  81. GRB060115: REM observations
  82. GRB 060116: ROTSE-III Optical Limits
  83. GRB060116: Faulkes North observation
  84. GRB 060116: Swift-BAT detection of a burst
  85. GRB 060115: Refined analysis of the Swift-BAT burst
  86. GRB 060115: Swift/UVOT upper limits
  87. GRB 060114: REM observations
  88. GRB 060114: Swift/UVOT Observations
  89. GRB060115, optical observation
  90. GRB 060115: MITSuME optical afterglow candidate
  91. GRB 060115: Swift detection of a burst
  92. GRB060114, optical observation
  93. GRB060114: Faulkes North observation
  94. GRB 060108: IR observations of afterglow
  95. GRB 060108: Evidence for an XRT Position Offset
  96. GRB 060110: KAIT observations
  97. GRB 060111B: MITSuME detection of optical afterglow
  98. GRB 060111B: TAROT optical observation
  99. GRB060111A: RTT150 optical observations
  100. GRB060111B: RTT150, possible host galaxy

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