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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"

2858 results found.

  1. GRB 100510A: MAXI/GSC detection
  2. GRB 100511A, RIMOTS optical upper limits
  3. GRB 100508A: Enhanced Swift-XRT position
  4. GRB100508A: Swift/UVOT Detection of the Afterglow
  5. GRB 100508A: Swift detection of a burst
  6. GRB 100504A: SARA-South Upper Limit
  7. GRB 100504A: Swift detection of a burst
  8. GRB 100424A: NOT optical observations
  9. GRB 100424A: Swift detection of a burst
  10. GRB 100420A: Swift detection of a burst
  11. GRB 100414A: IPN Localization
  12. GRB 100413B : Swift detection of a burst
  13. Short X-ray Transient detected by MAXI/GSC
  14. GRB 100305A Optical Observations
  15. GRB 100305A: Gemini-N OT candidate
  16. GRB 100213A: GRT Optical Observation
  17. GRB 100122A: Fermi GBM detection
  18. GRB100117A: Possible afterglow from NOT observation
  19. Konus-Wind observation of GRB 100103A
  20. GRB 100103A: a long GRB detected with INTEGRAL
  21. GRB 091221: Skynet/PROMPT Detections
  22. GRB 091221 Swift-BAT refined analysis
  23. GRB 091221: Swift detection of a burst
  24. Trigger 379449: Swift detection of a possible burst
  25. GRB 091208: ROTSE-III Optical Limits
  26. GRB 091123: Suzaku WAM observation of the prompt emission
  27. GRB 091109A: GROND confirmation of redshift z = 3.5
  28. GRB 091128: Fermi GBM detection
  29. GRB 091117A: Suzaku WAM observation of the prompt emission
  30. GRB 091112: Swift detection of a possible burst
  31. GRB 091102: ROTSE-III Optical Limits
  32. GRB 091031: Fermi GBM detection
  33. Radio afterglow detection from GRB 091020
  34. GRB 091020: Early TLS Multicolor detections, red afterglow
  35. GRB 091024: Swift-BAT refined analysis
  36. GRB091020 Swift/UVOT observations
  37. GRB 091020: Swift detection of a burst with an optical afterglow
  38. Trigger 371210: Swift/BAT Triggered on IGR J17511-3057
  39. GRB 090829B: Fermi GBM Detection
  40. GRB 090831B, RIMOTS optical upper limits
  41. GRB 090817: aphotometry of USNO-B1.0 341-0096763
  42. IPN Triangulation and Konus-Wind observaions of GRB090727B
  43. GRB 090727: Swift detection of a burst
  44. GRB 090711: Fermi GBM detection
  45. GRB 090726: Swift detection of a burst
  46. GRB 090715B: Lick observations
  47. GRB 090709A, RIMOTS optical upper limits
  48. GRB 090709B: Swift detection of a burst
  49. GRB 090709: Swift detection of a bright burst
  50. GRB 090705: Swift detection of a possible burst
  51. GRB 090529: CrAO optical upper limit
  52. GRB 090703: Fermi GBM detection
  53. GRB 090701: Fermi GBM detection
  54. GRB090618: OAA-OAUV Optical observations
  55. GRB 090617: Fermi GBM detection
  56. GRB 090616: Fermi GBM detection
  57. RXTE Discovery of Pulsations from SGR 0418+5729
  58. GRB 090528B: Fermi GBM detection
  59. GRB 090520C: Fermi GBM detection
  60. GRB 090519B: Fermi GBM detection
  61. GRB 090518B: Fermi GBM detection
  62. GRB 090323: optical observations
  63. GRB 090424: YNAO-GMG observations
  64. GRB 090427B: Fermi GBM detection
  65. GRB 090418: Optical observations with MITSuME Okayama and Ishigaki 1m telescope
  66. GRB 090417B: MITSuME Okayama optical upper limits
  67. GRB 090403: Fermi GBM detection
  68. GRB090401B, RIMOTS optical upper limits
  69. GRB 090330: Fermi GBM detection
  70. GRB 090323: Optical observation of xinglong TNT
  71. GRB 090323 TLS detection - still bright
  72. GRB 090323: UVOT Detection of Afterglow
  73. GRB 090323: Possible XRT Counterpart
  74. GRB090310: Fermi GBM detection
  75. IPN localization of GRB 090217
  76. SGR activity seen by BAT during ICSP Ionospheric Events
  77. GRB 090201: ROTSE-III Optical Limits
  78. Suzaku ToO Observation of AXP 1E 1547.0-5408
  79. Konus-Wind observation of AXP/SGR 1E1547.0-5408 bursting activity
  80. AXP 1E1547.0-5408: Fermi GBM detection of additional bursts
  81. AXP 1E1547.0-5408: INTEGRAL SPI-ACS confirms activity increase
  82. Fermi/GBM detection of GRB 081225
  83. GRB 081226: Swift-XRT refined analysis
  84. GRB081203A: BTA observation
  85. GRB 081216 : Fermi GBM observation
  86. Fermi Trig Num 251059717 = SGR 0044+42: MASTER prompt optical observations
  87. GRB 081207: Fermi GBM detection
  88. GRB 081211: Swift-BAT refined analysis
  89. GRB 081206: Fermi GBM detection
  90. GRB081203A: Ashra-1 observation of early optical and VHE-neutrino emission
  91. GRB 081126: Confirmation of the Optical Afterglow
  92. GRB 081126: optical observations
  93. GRB 081126: Swift-BAT refined analysis
  94. GRB 081126: Enhanced Swift-XRT position
  95. GRB 081126: Swift detection of a burst
  96. GRB 081119: Fermi GBM detection
  97. GRB 081110: MASTER: first optical observations Fermi GRB
  98. GRB 081109A, Swift-BAT refined analysis
  99. GRB 081109A optical upper limit
  100. GRB 081109: REM NIR afterglow detection

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