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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"

15987 results found.

  1. GRB 090205: Swift/UVOT Upper Limits
  2. GRB 090205: VLT refined redshift
  3. GRB 090205: Swift burst of interest
  4. GRB 090205: VLT spectroscopic redshift
  5. GRB090201: Swift UVOT upper limits
  6. GRB 090201: object inside the enhanced XRT error circle
  7. GRB 090201: VLT NIR observations
  8. GRB 090201: ROTSE-III Optical Limits
  9. GRB 090118: no afterglow candidate
  10. GRB 090123: Swift/UVOT Observations
  11. GRB 090118 (BATSS): GRT Optical Observation
  12. GRB 090118: Possible burst detection from Swift-BAT slew data
  13. GRB 090113: LOAO Detection Limits in R, I, z, Y-band
  14. GRB 090113: ROTSE-III Optical Limits
  15. GRB 090102: WSRT Radio Observations
  16. GRB 090107B: Swift/UVOT Observations
  17. GRB 090107B optical observations
  18. GRB 090107B: ROTSE-III Optical Limits
  19. GRB 090102: optical decay
  20. GRB 090102: GRT Optical Observation
  21. Swift triggered on the HMXB 1A 1118-61
  22. GRB 090102: Hobby-Eberly Telescope Spectroscopy
  23. GRB 090102: P60 Imaging and P200 Spectroscopy
  24. GRB 090102: GROND observations of the optical afterglow
  25. Swift UVOT observations of GRB 090102
  26. GRB 090102: NOT redshift
  27. GRB 090102: TAROT Calern observatory optical light curve
  28. GRB 090102: REM observations of a bright afterglow
  29. GRB 090102: Swift detection of a burst with an optical counterpart
  30. GRB 090102: TAROT Calern observatory optical observations
  31. GRB 081230 Swift/UVOT Observations
  32. GRB 081230: Swift/UVOT Detection of an Optical Afterglow
  33. GRB 081230: ROTSE-III Detection of Optical Counterpart
  34. GRB 081228: GROND confirmation of the optical/NIR afterglow
  35. VLA radio detection of GRB 081221
  36. GRB 081228: TAROT Calern observatory optical observations
  37. VLA radio observation of GRB 081221
  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 081222: MITSuME optical observation
  46. GRB 080810: optical observations
  47. GRB 081222:Optical afterglow observation
  48. VLA radio upper limit on GRB 081222
  49. GRB 081222: Gemini-South absorption redshift
  50. GRB 081221: Probable host galaxy in Keck imaging
  51. GRB081222 optical limit by "Pi of the Sky"
  52. Swift/UVOT observations of GRB 081221
  53. GRB 081222: Faulkes Telescope South observations
  54. GRB 081221: Gemini-N nIR imaging
  55. GRB081222, optical observation
  56. GRB081222: Swift/UVOT detection of an optical afterglow
  57. GRB081203A: BTA observation
  58. GRB 081222: GROND Detection of the Optical/NIR Afterglow
  59. GRB 081222: Swift detection of a burst with a bright optical afterglow
  60. GRB 081221: further NOT observations
  61. Fermi Trig Num 251059717 = SGR 0044+42: MASTER prompt optical observations
  62. GRB 0811215A: MASTER prompt optical observations
  63. GRB 081210: optical observations
  64. GRB 081007: Detection of a Supernova
  65. GRB 081211B(?): Possible burst detection from Swift-BAT slew data
  66. GRB 081210, SMARTS optical/IR observations
  67. GRB 081211: Swift/UVOT detection of an optical afterglow
  68. GRB 081210: Swift/UVOT refined analysis
  69. GRB081203B: optical observations
  70. GRB 081210: Swift detection of a burst with optical afterglow
  71. GRB 081203A: optical observations
  72. Radio observation of GRB 081121 with ATCA
  73. Radio observation of GRB 081118 with ATCA
  74. GRB 081128: afterglow observations
  75. GRB 081203B: Additional Gemini imaging
  76. Radio observation of GRB 081109 with ATCA
  77. Radio observation of GRB 081104 with ATCA
  78. Radio observation of GRB 081029 with ATCA
  79. Radio observation of GRB 081008 with ATCA
  80. GRB081203A: Ashra-1 observation of early optical and VHE-neutrino emission
  81. GRB 081203B: Gemini observations
  82. GRB 081128: optical observation in CrAO
  83. GRB081203A: Optical observations at Ishigaki
  84. GRB 081128: Optical afterglow observations
  85. GRB081203B: optical observations
  86. Radio detection of GRB 081203B with the VLA
  87. GRB081203A: Radio upper limit at 15 GHz
  88. GRB 081204: Swift/UVOT Upper Limits
  89. GRB081203A: MITSuME optical observation
  90. GRB 081203A: Optical observations of Xinglong TNT telescope
  91. GRB081203A: optical observation
  92. GRB 081203B: optical observations
  93. GRB 081203B: SDSS upper limits at the position of the optical afterglow
  94. GRB 081203A: optical observations
  95. Swift UVOT observations of GRB 081203A
  96. GRB 081130B: MASTER prompt optical observations
  97. GRB081203: optical observation
  98. GRB 081203: Swift detection of a burst with a bright optical counterpart
  99. GRB 081128: optical observation
  100. GRB 081130: MASTER VWF prompt optical observations Fermi GRB

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