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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"
  1. ICECUBE-160427A neutrino candidate event: updated direction information
  2. MASTER search for counterpart to the IceCube event 67093193 (run 127853)
  3. Archival observations by HAWC of IceCube HESE event of April 27, 2016
  4. Fermi/LAT search for counterpart to the IceCube event 67093193 (run 127853)
  5. GRB 160422A: XRT Afterglow Confirmation
  6. LSGT observation of GRB 160425A
  7. GRB 160425A: Swift/UVOT Detection
  8. GRB 160425A: Skynet PROMPT-CTIO observations of the optical afterglow
  9. GRB 160425A: Swift-BAT refined analysis
  10. GRB 160425A: SMARTS optical/IR observations
  11. GRB 160325A: Skynet PROMPT-CTIO observations of the optical afterglow
  12. GRB 160422A: GROND NIR afterglow detection
  13. GRB 160425A MASTER notices: possible host galaxy in the optical error-box
  14. GRB 160425A VLT/X-shooter redshift
  15. GRB 160425A: GROND observation
  16. GRB 160425A: Swift-XRT refined Analysis
  17. GRB 160425A: Enhanced Swift-XRT position
  18. GRB 160422A: Swift/UVOT Afterglow Confirmation
  19. GRB 160422A: CALET Gamma-Ray Burst Monitor detection
  20. GRB 160425A : MASTER earlier optical observations
  21. GRB 160425A: Swift detection of an unusual burst with an optical afterglow
  22. Konus-Wind observation of GRB 160424A
  23. LIGO/Virgo G197392 / LVT151012: Identification of a GW CBC Candidate
  24. GRB 160424A: Fermi GBM observation
  25. GRB 160424A - XRT position uncertain
  26. GRB 160424A: Swift-BAT refined analysis
  27. GRB 160424A: Swift/UVOT Upper Limit
  28. GRB 160424A: Swift-XRT observations
  29. GRB 160424A: Swift detection of a burst
  30. GRB 160422A: Swift-XRT afterglow detection
  31. GRB 160422A: Swift/UVOT Candidate Afterglow
  32. GRB 160419A: CALET Gamma-Ray Burst Monitor detection
  33. GRB 160422A: Fermi GBM observation
  34. GRB 160422A: Swift ToO observations
  35. GRB 160422A: Fermi-LAT Detection
  36. GRB 160419A, Swift-BAT refined analysis
  37. GRB 160419A: Fermi GBM detection
  38. GRB 160419A: Swift detection of a burst
  39. Fermi GBM trigger 482632364/160418023 is not a GRB
  40. GRB 160417A: GMG observations
  41. GRB 160417A: Swift-BAT refined analysis
  42. GRB 160417A: Swift/UVOT Detection
  43. GRB 160417A: iTelescope T11 optical observations
  44. GRB 160417A: Swift-XRT refined Analysis
  45. GRB 160417A: MITSuME Okayama upper limits
  46. GRB 160417A: Enhanced Swift-XRT position
  47. GRB 160417A: KAIT optical afterglow confirmation
  48. GRB 160417A: Swift detection of a burst with an optical counterpart
  49. LIGO/Virgo G211117: EWE for NOWT of 12 days follow-up of northern sky
  50. GRB 160412A: GROND upper limits
  51. GRB 160411A - Gemini-S afterglow candidate
  52. Konus-Wind observation of GRB 160409A
  53. GRB 160410A: SMARTS optical/IR observations
  54. LIGO Virgo G211117: Additional MWA Observations
  55. GRB 160410A: TLS Tautenburg observations
  56. GRB 160412A: Swift/UVOT Upper Limits
  57. Swift Trigger 682614 is not a GRB
  58. GRB 160410A: JCMT SCUBA-2 sub-mm observation
  59. GRB 160409A: Swift-XRT observations
  60. GRB 160409A found in Swift BAT ground analysis
  61. GRB 160412A: Swift-XRT refined Analysis
  62. GRB 160411A: Swift-BAT refined analysis of the short burst
  63. GRB 160412A: Swift-BAT refined analysis
  64. GRB 160410A: further NOT optical observations
  65. GRB 160412A: Enhanced Swift-XRT position
  66. GRB 160412A: Swift detection of a burst
  67. GRB 160408A: CALET Gamma-Ray Burst Monitor detection
  68. GRB 160409A: Swift ToO observations
  69. GRB 160410A: NOT observations of the afterglow
  70. GRB 160408A: 6.0 GHz VLA upper limit
  71. GRB 160411A: Gemini-S optical observations
  72. GRB 160411A: GROND Optical/NIR upper limits
  73. GRB 160411A: Swift/UVOT Upper Limits
  74. GRB 160410A: UKIRT near-IR upper limits
  75. GRB 160411A: Fermi GBM detection
  76. Konus-Wind observation of GRB 160410A (short/hard)
  77. GRB 160410A: TAROT La Silla observatory early optical observations
  78. GRB 160411A: Swift-XRT refined Analysis
  79. GRB 160410A: MITSuME Akeno optical upper limits
  80. GRB 160411A: MASTER-NET early optical observations.
  81. GRB 160411A: Enhanced Swift-XRT position
  82. GRB 160410A: Swift-XRT refined Analysis
  83. GRB 160411A: Swift-XRT observations
  84. GRB 160410A: GMG observation
  85. GRB 160411A: Swift detection of a short burst
  86. GRB 160410A: Keck-I/LRIS redshift
  87. GRB 160410A: Skynet PROMPT-CTIO observations of the optical afterglow
  88. GRB 160410A: Swift-BAT refined analysis of the short GRB
  89. GRB 160410A: Swift/UVOT Detection
  90. GRB 160410A: VLT/X-shooter redshift
  91. GRB 160410A: Enhanced Swift-XRT position
  92. GRB 160410A: GROND optical detection
  93. GRB 160410A: Swift detection of a (possibly-short) burst with an optical counterpart
  94. GRB 160408A: GMG observation limit
  95. GRB 160408A: Gemini afterglow confirmation
  96. GRB 160408A: TLS Tautenburg observations
  97. GRB 160408A: Swift/UVOT Upper Limits
  98. GRB 160408A: Swift-XRT refined Analysis
  99. GRB 160408A: Fermi GBM detection
  100. GRB 160406A: Fermi GBM observation

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