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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"

24817 results found.

  1. SGR 1935+2154: AbAO optical upper limit
  2. Trigger 686761: Swift detection of a bright burst from SGR 1935+2154
  3. Trigger 686443: Swift detection of SGR 1935+2154
  4. FACT follow-up of the IceCube event 160427A
  5. Interplanetary Network Search for IceCube 160427A
  6. GRB 160509A: CALET Gamma-Ray Burst Monitor detection
  7. GRB 160509A: non-observation of VHE emission with HAWC
  8. GRB 160509A: TLS Tautenburg Afterglow Detection
  9. GRB 160509A Gemini North redshift
  10. GRB 160509A: Fermi-LAT refined analysis
  11. GRB 160509A: Fermi GBM Detection
  12. GRB 160509A Gemini North candidate afterglow
  13. GRB 160509A: optical observations
  14. GRB 160509A: Swift-XRT afterglow detection
  15. Correction to GCN 19404; GRB 160509A: MAXI/GSC detection
  16. GRB 160227A: MAXI/GSC detection
  17. GRB 160506A: TAROT La Silla observatory optical observations
  18. LIGO/Virgo G211117: Astrosat CZTI upper limits
  19. GRB 160506A: IRSF upper limits
  20. GRB 160506A: Swift-XRT refined Analysis
  21. GRB 160506A: Swift/UVOT Upper Limits
  22. GRB 160506A: Swift-BAT refined analysis
  23. GRB 160506A: GROND upper limits
  24. GRB 160506A: Enhanced Swift-XRT position
  25. GRB 160506A: Swift detection of a burst
  26. GRB 160504A: Swift-BAT refined analysis
  27. GRB 160504A: RATIR Optical and NIR Observations
  28. GRB 160504A: Swift/UVOT Upper Limits
  29. GRB 160504A: Bassano Bresciano Observatory upper limits
  30. GRB 160504A: Swift-XRT refined Analysis
  31. GRB 160504A: Enhanced Swift-XRT position
  32. GRB 160504A: NOT upper limits
  33. GRB 160417A, the review of the sky area in plate archive
  34. GRB 160504A: TAROT Calern observatory optical observations
  35. GRB 160504A: Swift detection of a burst
  36. ICECUBE-160427A : Pan-STARRS imaging and optical transients in the field
  37. GRB 160503A: Fermi GBM observation
  38. VERITAS rapid follow-up observations of IceCube event 160427A
  39. GRB 160501A: Swift-BAT refined analysis
  40. GRB 160501A: GROND Upper limits
  41. GRB 160501A: MITSuME Okayama upper limits
  42. GRB 160501A: UKIRT near-IR upper limits
  43. GRB 160501A: Swift/UVOT Upper Limits
  44. GRB 160501A: Swift-XRT refined Analysis
  45. GRB 160501A: RATIR Optical and NIR Observations
  46. GRB 160501A: Enhanced Swift-XRT position
  47. GRB 160501A: TAROT Calern observatory optical observations
  48. GRB 160501A: NOT optical and NIR observations
  49. GRB 160501A: Swift detection of a burst
  50. Archival observations by HAWC of IceCube HESE event of April 27, 2016
  51. Fermi/LAT search for counterpart to the IceCube event 67093193 (run 127853)
  52. GRB 160422A: XRT Afterglow Confirmation
  53. LSGT observation of GRB 160425A
  54. GRB 160425A: Swift/UVOT Detection
  55. GRB 160425A: Skynet PROMPT-CTIO observations of the optical afterglow
  56. GRB 160425A: Swift-BAT refined analysis
  57. GRB 160325A: Skynet PROMPT-CTIO observations of the optical afterglow
  58. GRB 160422A: GROND NIR afterglow detection
  59. GRB 160425A MASTER notices: possible host galaxy in the optical error-box
  60. GRB 160425A: GROND observation
  61. GRB 160425A: Swift-XRT refined Analysis
  62. GRB 160425A: Enhanced Swift-XRT position
  63. GRB 160422A: Swift/UVOT Afterglow Confirmation
  64. GRB 160422A: CALET Gamma-Ray Burst Monitor detection
  65. GRB 160425A: Swift detection of an unusual burst with an optical afterglow
  66. LIGO/Virgo G197392 / LVT151012: Identification of a GW CBC Candidate
  67. GRB 160424A: Swift-BAT refined analysis
  68. GRB 160424A: Swift-XRT observations
  69. GRB 160422A: Swift-XRT afterglow detection
  70. GRB 160422A: Swift/UVOT Candidate Afterglow
  71. GRB 160422A: Fermi GBM observation
  72. GRB 160422A: Fermi-LAT Detection
  73. GRB 160419A, Swift-BAT refined analysis
  74. GRB 160417A: GMG observations
  75. GRB 160417A: Swift-BAT refined analysis
  76. GRB 160417A: Swift/UVOT Detection
  77. GRB 160417A: Swift-XRT refined Analysis
  78. GRB 160417A: MITSuME Okayama upper limits
  79. GRB 160417A: Enhanced Swift-XRT position
  80. GRB 160417A: Swift detection of a burst with an optical counterpart
  81. LIGO/Virgo G211117: EWE for NOWT of 12 days follow-up of northern sky
  82. GRB 160412A: GROND upper limits
  83. Konus-Wind observation of GRB 160409A
  84. GRB 160410A: TLS Tautenburg observations
  85. GRB 160412A: Swift/UVOT Upper Limits
  86. GRB 160409A: Swift-XRT observations
  87. GRB 160409A found in Swift BAT ground analysis
  88. GRB 160412A: Swift-XRT refined Analysis
  89. GRB 160411A: Swift-BAT refined analysis of the short burst
  90. GRB 160412A: Swift-BAT refined analysis
  91. GRB 160412A: Enhanced Swift-XRT position
  92. GRB 160412A: Swift detection of a burst
  93. GRB 160408A: 6.0 GHz VLA upper limit
  94. GRB 160411A: GROND Optical/NIR upper limits
  95. GRB 160411A: Swift/UVOT Upper Limits
  96. GRB 160410A: UKIRT near-IR upper limits
  97. Konus-Wind observation of GRB 160410A (short/hard)
  98. GRB 160410A: TAROT La Silla observatory early optical observations
  99. GRB 160411A: Swift-XRT refined Analysis
  100. GRB 160411A: Enhanced Swift-XRT position

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