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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"

2851 results found.

  1. GRB 100424A: NOT optical observations
  2. GRB 100424A: Swift detection of a burst
  3. GRB 100420A: Swift detection of a burst
  4. GRB 100414A: IPN Localization
  5. GRB 100413B : Swift detection of a burst
  6. Short X-ray Transient detected by MAXI/GSC
  7. GRB 100305A Optical Observations
  8. GRB 100305A: Gemini-N OT candidate
  9. GRB 100213A: GRT Optical Observation
  10. GRB 100122A: Fermi GBM detection
  11. GRB100117A: Possible afterglow from NOT observation
  12. Konus-Wind observation of GRB 100103A
  13. GRB 100103A: a long GRB detected with INTEGRAL
  14. GRB 091221: Skynet/PROMPT Detections
  15. GRB 091221 Swift-BAT refined analysis
  16. GRB 091221: Swift detection of a burst
  17. Trigger 379449: Swift detection of a possible burst
  18. GRB 091208: ROTSE-III Optical Limits
  19. GRB 091123: Suzaku WAM observation of the prompt emission
  20. GRB 091109A: GROND confirmation of redshift z = 3.5
  21. GRB 091128: Fermi GBM detection
  22. GRB 091117A: Suzaku WAM observation of the prompt emission
  23. GRB 091112: Swift detection of a possible burst
  24. GRB 091102: ROTSE-III Optical Limits
  25. GRB 091031: Fermi GBM detection
  26. Radio afterglow detection from GRB 091020
  27. GRB 091020: Early TLS Multicolor detections, red afterglow
  28. GRB 091024: Swift-BAT refined analysis
  29. GRB091020 Swift/UVOT observations
  30. GRB 091020: Swift detection of a burst with an optical afterglow
  31. Trigger 371210: Swift/BAT Triggered on IGR J17511-3057
  32. GRB 090829B: Fermi GBM Detection
  33. GRB 090831B, RIMOTS optical upper limits
  34. GRB 090817: aphotometry of USNO-B1.0 341-0096763
  35. IPN Triangulation and Konus-Wind observaions of GRB090727B
  36. GRB 090727: Swift detection of a burst
  37. GRB 090711: Fermi GBM detection
  38. GRB 090726: Swift detection of a burst
  39. GRB 090715B: Lick observations
  40. GRB 090709A, RIMOTS optical upper limits
  41. GRB 090709B: Swift detection of a burst
  42. GRB 090709: Swift detection of a bright burst
  43. GRB 090705: Swift detection of a possible burst
  44. GRB 090529: CrAO optical upper limit
  45. GRB 090703: Fermi GBM detection
  46. GRB 090701: Fermi GBM detection
  47. GRB090618: OAA-OAUV Optical observations
  48. GRB 090617: Fermi GBM detection
  49. GRB 090616: Fermi GBM detection
  50. RXTE Discovery of Pulsations from SGR 0418+5729
  51. GRB 090528B: Fermi GBM detection
  52. GRB 090520C: Fermi GBM detection
  53. GRB 090519B: Fermi GBM detection
  54. GRB 090518B: Fermi GBM detection
  55. GRB 090323: optical observations
  56. GRB 090424: YNAO-GMG observations
  57. GRB 090427B: Fermi GBM detection
  58. GRB 090418: Optical observations with MITSuME Okayama and Ishigaki 1m telescope
  59. GRB 090417B: MITSuME Okayama optical upper limits
  60. GRB 090403: Fermi GBM detection
  61. GRB090401B, RIMOTS optical upper limits
  62. GRB 090330: Fermi GBM detection
  63. GRB 090323: Optical observation of xinglong TNT
  64. GRB 090323 TLS detection - still bright
  65. GRB 090323: UVOT Detection of Afterglow
  66. GRB 090323: Possible XRT Counterpart
  67. GRB090310: Fermi GBM detection
  68. IPN localization of GRB 090217
  69. SGR activity seen by BAT during ICSP Ionospheric Events
  70. GRB 090201: ROTSE-III Optical Limits
  71. Suzaku ToO Observation of AXP 1E 1547.0-5408
  72. Konus-Wind observation of AXP/SGR 1E1547.0-5408 bursting activity
  73. AXP 1E1547.0-5408: Fermi GBM detection of additional bursts
  74. AXP 1E1547.0-5408: INTEGRAL SPI-ACS confirms activity increase
  75. Fermi/GBM detection of GRB 081225
  76. GRB 081226: Swift-XRT refined analysis
  77. GRB081203A: BTA observation
  78. GRB 081216 : Fermi GBM observation
  79. Fermi Trig Num 251059717 = SGR 0044+42: MASTER prompt optical observations
  80. GRB 081207: Fermi GBM detection
  81. GRB 081211: Swift-BAT refined analysis
  82. GRB 081206: Fermi GBM detection
  83. GRB081203A: Ashra-1 observation of early optical and VHE-neutrino emission
  84. GRB 081126: Confirmation of the Optical Afterglow
  85. GRB 081126: optical observations
  86. GRB 081126: Swift-BAT refined analysis
  87. GRB 081126: Enhanced Swift-XRT position
  88. GRB 081126: Swift detection of a burst
  89. GRB 081119: Fermi GBM detection
  90. GRB 081110: MASTER: first optical observations Fermi GRB
  91. GRB 081109A, Swift-BAT refined analysis
  92. GRB 081109A optical upper limit
  93. GRB 081109: REM NIR afterglow detection
  94. GRB 081109: Swift detection of a burst
  95. GRB 081107: Fermi GBM detection
  96. GRB 081104: Swift detection of a burst
  97. Fermi LAT/GBM short-hard GRB 081024B: Possible TLS Afterglow (Corrected)
  98. Fermi LAT/GBM short-hard GRB 081024B: Possible TLS Afterglow
  99. GRB 081024: KAIT Optical Limits
  100. Detection of flare star Algol in Swift-BAT slew data

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