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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"

3137 results found.

  1. GRB 091221 Swift-BAT refined analysis
  2. GRB 091221: Swift detection of a burst
  3. Trigger 379449: Swift detection of a possible burst
  4. GRB 091208: ROTSE-III Optical Limits
  5. GRB 091123: Suzaku WAM observation of the prompt emission
  6. GRB 091109A: GROND confirmation of redshift z = 3.5
  7. GRB 091128: Fermi GBM detection
  8. GRB 091117A: Suzaku WAM observation of the prompt emission
  9. GRB 091112: Swift detection of a possible burst
  10. GRB 091102: ROTSE-III Optical Limits
  11. GRB 091031: Fermi GBM detection
  12. Radio afterglow detection from GRB 091020
  13. GRB 091020: Early TLS Multicolor detections, red afterglow
  14. GRB 091024: Swift-BAT refined analysis
  15. GRB091020 Swift/UVOT observations
  16. GRB 091020: Swift detection of a burst with an optical afterglow
  17. Trigger 371210: Swift/BAT Triggered on IGR J17511-3057
  18. GRB 090829B: Fermi GBM Detection
  19. GRB 090831B, RIMOTS optical upper limits
  20. GRB 090817: aphotometry of USNO-B1.0 341-0096763
  21. IPN Triangulation and Konus-Wind observaions of GRB090727B
  22. GRB 090727: Swift detection of a burst
  23. GRB 090711: Fermi GBM detection
  24. GRB 090726: Swift detection of a burst
  25. GRB 090715B: Lick observations
  26. GRB 090709A, RIMOTS optical upper limits
  27. GRB 090709B: Swift detection of a burst
  28. GRB 090709: Swift detection of a bright burst
  29. GRB 090705: Swift detection of a possible burst
  30. GRB 090529: CrAO optical upper limit
  31. GRB 090703: Fermi GBM detection
  32. GRB 090701: Fermi GBM detection
  33. GRB090618: OAA-OAUV Optical observations
  34. GRB 090617: Fermi GBM detection
  35. GRB 090616: Fermi GBM detection
  36. RXTE Discovery of Pulsations from SGR 0418+5729
  37. GRB 090528B: Fermi GBM detection
  38. GRB 090520C: Fermi GBM detection
  39. GRB 090519B: Fermi GBM detection
  40. GRB 090518B: Fermi GBM detection
  41. GRB 090323: optical observations
  42. GRB 090424: YNAO-GMG observations
  43. GRB 090427B: Fermi GBM detection
  44. GRB 090418: Optical observations with MITSuME Okayama and Ishigaki 1m telescope
  45. GRB 090417B: MITSuME Okayama optical upper limits
  46. GRB 090403: Fermi GBM detection
  47. GRB090401B, RIMOTS optical upper limits
  48. GRB 090330: Fermi GBM detection
  49. GRB 090323: Optical observation of xinglong TNT
  50. GRB 090323 TLS detection - still bright
  51. GRB 090323: UVOT Detection of Afterglow
  52. GRB 090323: Possible XRT Counterpart
  53. GRB090310: Fermi GBM detection
  54. IPN localization of GRB 090217
  55. SGR activity seen by BAT during ICSP Ionospheric Events
  56. GRB 090201: ROTSE-III Optical Limits
  57. Suzaku ToO Observation of AXP 1E 1547.0-5408
  58. Konus-Wind observation of AXP/SGR 1E1547.0-5408 bursting activity
  59. AXP 1E1547.0-5408: Fermi GBM detection of additional bursts
  60. AXP 1E1547.0-5408: INTEGRAL SPI-ACS confirms activity increase
  61. Fermi/GBM detection of GRB 081225
  62. GRB 081226: Swift-XRT refined analysis
  63. GRB081203A: BTA observation
  64. GRB 081216 : Fermi GBM observation
  65. Fermi Trig Num 251059717 = SGR 0044+42: MASTER prompt optical observations
  66. GRB 081207: Fermi GBM detection
  67. GRB 081211: Swift-BAT refined analysis
  68. GRB 081206: Fermi GBM detection
  69. GRB081203A: Ashra-1 observation of early optical and VHE-neutrino emission
  70. GRB 081126: Confirmation of the Optical Afterglow
  71. GRB 081126: optical observations
  72. GRB 081126: Swift-BAT refined analysis
  73. GRB 081126: Enhanced Swift-XRT position
  74. GRB 081126: Swift detection of a burst
  75. GRB 081119: Fermi GBM detection
  76. GRB 081110: MASTER: first optical observations Fermi GRB
  77. GRB 081109A, Swift-BAT refined analysis
  78. GRB 081109A optical upper limit
  79. GRB 081109: REM NIR afterglow detection
  80. GRB 081109: Swift detection of a burst
  81. GRB 081107: Fermi GBM detection
  82. GRB 081104: Swift detection of a burst
  83. Fermi LAT/GBM short-hard GRB 081024B: Possible TLS Afterglow (Corrected)
  84. Fermi LAT/GBM short-hard GRB 081024B: Possible TLS Afterglow
  85. GRB 081024: KAIT Optical Limits
  86. Detection of flare star Algol in Swift-BAT slew data
  87. Fermi GBM detection of additional bursts from AXP 1E1547.0-5408
  88. AXP 1E1547.0-5408 (SGR 1550-5418): Fermi GBM detection
  89. GRB 080925: Suzaku WAM observation of the prompt emission
  90. GRB081001: SuperAGILE Localization of a long GRB
  91. GRB 080919: Swift-XRT refined analysis
  92. GRB 080919: REM NIR observations
  93. INTEGRAL ToO observation of SGR0501+4516
  94. Swift trigger 322590: BAT detection of a possible burst
  95. SGR 0501+4516: Swift XRT measure of the spin period
  96. GRB080823: Fermi Gamma-ray Burst Monitor detection
  97. GRB080805 optical limit by "Pi of the Sky"
  98. GRB 080805: Swift detection of a burst
  99. GRB 080725, Swift-BAT refined analysis
  100. GRB 080721, Swift-BAT refined analysis

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