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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"

20382 results found.

  1. GRB 090113: ROTSE-III Optical Limits
  2. GRB 090113: Swift detection of a burst
  3. GRB 090112: Fermi GBM detection
  4. GRB 090111: Swift UVOT Upper Limits
  5. GRB 090111: Swift-XRT refined analysis
  6. GRB 090111: Enhanced Swift-XRT position
  7. GRB 090111: Swift detection of a burst
  8. GRB 090107B: Swift XRT afterglow confirmation
  9. GRB 090107B: Swift/UVOT Observations
  10. GRB 090107B: Swift-XRT detection of possible afterglow
  11. VLA radio upper limit on GRB 090102
  12. GRB 090102: GRT Optical Observation
  13. Swift triggered on the HMXB 1A 1118-61
  14. GRB 090102: P60 Imaging and P200 Spectroscopy
  15. GRB 090102 Observations from IAC80
  16. GRB 090102: GROND observations of the optical afterglow
  17. GRB 090102: Swift-BAT refined analysis
  18. GRB 090102: NOT redshift
  19. GRB 090102: Enhanced Swift-XRT position
  20. GRB 090102: REM observations of a bright afterglow
  21. GRB 090102: Swift detection of a burst with an optical counterpart
  22. GRB 090102: TAROT Calern observatory optical observations
  23. GRB 081230: GROND confirmation of the afterglow
  24. GRB081230: Swift-XRT refined analysis
  25. GRB 081230 Swift/UVOT Observations
  26. GRB 081230: Enhanced Swift-XRT position
  27. GRB 081230: Swift detection of a burst
  28. GRB 081228, Swift-BAT refined analysis
  29. VLA radio detection of GRB 081221
  30. GRB 081228: Swift/UVOT Upper Limits
  31. GRB 081228: Swift-XRT Team refined analysis
  32. GRB 081228: detection by GROND
  33. GRB 081228: Enhanced Swift-XRT position
  34. GRB 081228: TAROT Calern observatory optical observations
  35. GRB 081228: Swift detection of a burst
  36. VLA radio observation of GRB 081221
  37. GRB 081226B: Swift XRT and UVOT upper limits
  38. GRB 081226: Swift-XRT refined analysis
  39. GRB 081226A: Swift UVOT Upper Limits
  40. GRB 081226: GROND afterglow candidate
  41. GRB 081226: ROTSE-III Optical Limits
  42. GRB 081226: Swift detection of a possible short-hard burst
  43. GRB 080810: optical observations
  44. GRB 081211B: optical observations
  45. GRB 081224: Swift-XRT observation
  46. GRB 081222: MITSuME optical observation
  47. GRB 081221: GROND observations
  48. VLA radio upper limit on GRB 081222
  49. GRB 081221: Probable host galaxy in Keck imaging
  50. GRB 081222, Swift-BAT refined analysis
  51. GRB081222 optical limit by "Pi of the Sky"
  52. Konus-Wind observation of very bright GRB 081215A
  53. GRB 081222: Swift XRT refined analysis
  54. IPN triangulation of bright GRB 081215A
  55. GRB 081222: Faulkes Telescope South observations
  56. GRB 081221: Gemini-N nIR imaging
  57. GRB081222, optical observation
  58. GRB081203A: BTA observation
  59. Konus-Wind observation of GRB 081221
  60. GRB 081222: GROND Detection of the Optical/NIR Afterglow
  61. GRB081222: REM candidate afterglow
  62. GRB 081222: Swift detection of a burst with a bright optical afterglow
  63. GRB 081221: Enhanced Swift-XRT position
  64. GRB 081221: further NOT observations
  65. GRB 081221: NOT observations
  66. GRB 081221: Swift detection of a burst
  67. GRB 081118: Zadko observations
  68. Fermi Trig Num 251059717 = SGR 0044+42: MASTER prompt optical observations
  69. GRB 0811215A: MASTER prompt optical observations
  70. GRB 081215A: Andromeda inside Fermi error box: MASTER observations
  71. GRB 0811215A: Andromeda inside Fermi error box: MASTER observations
  72. Possible GRB 081211B: Swift/UVOT Upper Limits
  73. Possible GRB 081211B - Swift-XRT analysis
  74. GRB 081207: Fermi GBM detection
  75. GRB 081211B(?): Possible burst detection from Swift-BAT slew data
  76. GRB 081210, SMARTS optical/IR observations
  77. GRB 081211: Enhanced Swift-XRT position
  78. GRB 081211: Swift detection of a burst
  79. GRB081203B: optical observations
  80. GRB 081210: Enhanced Swift-XRT position
  81. GRB 081210: Swift detection of a burst with optical afterglow
  82. IPN triangulation of short hard GRB 081209
  83. GRB 081203A: optical observations
  84. GRB 081128: afterglow observations
  85. GRB081203A: Ashra-1 observation of early optical and VHE-neutrino emission
  86. GRB 081128: optical observation in CrAO
  87. GRB081203A: Optical observations at Ishigaki
  88. GRB 081204: GROND Observations
  89. Radio detection of GRB 081203B with the VLA
  90. GRB081203A: Radio upper limit at 15 GHz
  91. GRB 081204B: Fermi GBM detection
  92. GRB 081204: Swift/UVOT Upper Limits
  93. GRB 081204: Swift XRT afterglow confirmation
  94. GRB081203A: MITSuME optical observation
  95. GRB081203A: optical observation
  96. VLA Radio upper limit on GRB 081203A
  97. GRB 081203B: optical observations
  98. Swift/UVOT detection of GRB081203B
  99. GRB 081203B: Swift-XRT candidate afterglow.
  100. GRB 081203A: optical observations

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