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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"

19089 results found.

  1. LSGT observation of GRB 160425A
  2. GRB 160425A: Swift/UVOT Detection
  3. GRB 160425A: Skynet PROMPT-CTIO observations of the optical afterglow
  4. GRB 160325A: Skynet PROMPT-CTIO observations of the optical afterglow
  5. GRB 160422A: GROND NIR afterglow detection
  6. GRB 160425A VLT/X-shooter redshift
  7. GRB 160425A: GROND observation
  8. GRB 160425A: Enhanced Swift-XRT position
  9. GRB 160422A: Swift/UVOT Afterglow Confirmation
  10. GRB 160422A: CALET Gamma-Ray Burst Monitor detection
  11. GRB 160425A: Swift detection of an unusual burst with an optical afterglow
  12. GRB 160424A: Swift-XRT observations
  13. GRB 160422A: Swift/UVOT Candidate Afterglow
  14. GRB 160422A: Swift ToO observations
  15. GRB 160422A: Fermi-LAT Detection
  16. GRB 160419A, Swift-BAT refined analysis
  17. GRB 160417A: GMG observations
  18. GRB 160417A: Swift/UVOT Detection
  19. GRB 160417A: Swift-XRT refined Analysis
  20. GRB 160417A: MITSuME Okayama upper limits
  21. GRB 160417A: Enhanced Swift-XRT position
  22. GRB 160417A: Swift detection of a burst with an optical counterpart
  23. GRB 160412A: GROND upper limits
  24. GRB 160410A: TLS Tautenburg observations
  25. GRB 160412A: Swift/UVOT Upper Limits
  26. GRB 160409A: Swift-XRT observations
  27. GRB 160409A found in Swift BAT ground analysis
  28. GRB 160411A: Swift-BAT refined analysis of the short burst
  29. GRB 160412A: Enhanced Swift-XRT position
  30. GRB 160412A: Swift detection of a burst
  31. GRB 160408A: CALET Gamma-Ray Burst Monitor detection
  32. GRB 160409A: Swift ToO observations
  33. GRB 160408A: 6.0 GHz VLA upper limit
  34. GRB 160411A: GROND Optical/NIR upper limits
  35. GRB 160411A: Swift/UVOT Upper Limits
  36. GRB 160410A: UKIRT near-IR upper limits
  37. GRB 160410A: TAROT La Silla observatory early optical observations
  38. GRB 160411A: Enhanced Swift-XRT position
  39. GRB 160411A: Swift-XRT observations
  40. GRB 160410A: GMG observation
  41. GRB 160410A: Skynet PROMPT-CTIO observations of the optical afterglow
  42. GRB 160410A: Swift-BAT refined analysis of the short GRB
  43. GRB 160410A: Swift/UVOT Detection
  44. GRB 160410A: Enhanced Swift-XRT position
  45. GRB 160410A: GROND optical detection
  46. GRB 160410A: Swift detection of a (possibly-short) burst with an optical counterpart
  47. GRB 160408A: GMG observation limit
  48. GRB 160408A: TLS Tautenburg observations
  49. GRB 160408A: Swift/UVOT Upper Limits
  50. GRB 160408A: Gemini optical observations
  51. GRB 160408A: Enhanced Swift-XRT position
  52. GRB 160408A: Swift detection of a short burst
  53. IPN Triangulation of GRB 160406A (short/hard)
  54. GRB 160401A: Swift-XRT observations
  55. GRB 160401A: Swift/UVOT Upper Limits
  56. GRB 160401A: Zadko observatory - Gingin optical observations
  57. GRB 160401A: Swift ToO observations
  58. GRB 160327A: Continued RATIR Optical and NIR Observations
  59. LIGO/Virgo G211117: LOFAR follow-up
  60. GRB 160327A: Imaging and spectroscopy from GTC
  61. GRB 160327A: Continued RATIR Optical and NIR Observations
  62. GRB 160327A: Mondy optical upper limit
  63. GRB 160327A: Swift/UVOT Upper Limits
  64. GRB 160327A: Enhanced Swift-XRT position
  65. GRB 160327A: RATIR Optical and NIR Afterglow Detection
  66. GRB 160327A: Swift detection of a burst
  67. GRB 160325A: GROND Upper Limits
  68. GRB 160325A: afterglow confirmation
  69. GRB 160325A: Enhanced Swift-XRT position
  70. Swift Trigger 680457 is not a GRB
  71. LIGO/Virgo G211117: CALET GBM Observations
  72. GRB160325A: REM NIR observations
  73. GRB 160325A: Swift detection of a burst
  74. Swift detects GX 301-2 in very high state
  75. GRB 160321A: AbAO optical observations
  76. GRB 160321A: Possible RATIR Optical and NIR Detections
  77. GRB 160321A: Swift/UVOT Upper Limits
  78. GRB 160321A: Swift-XRT refined Analysis
  79. GRB 160316A: CALET Gamma-Ray Burst Monitor detection
  80. GRB 160321A: Enhanced Swift-XRT position
  81. GRB 160321A: Swift detection of a probable burst
  82. GRB 160310A: Terskol 2-m observations
  83. IPN Triangulation of GRB 160310A
  84. LIGO/Virgo G211117: EWE for NOWT follow-up of northern sky
  85. GRB 160310A: A further Swift-XRT observation, no afterglow detected
  86. Swift detection of a likely new SGR: SGR 0755-2933
  87. GRB 160314A: Continued RATIR Optical and NIR Observations
  88. GRB 160313A: Mondy optical upper limit
  89. GRB 160314A: GROND optical/NIR observations
  90. GRB 160314A: ISON-Ussuriysk optical upper limit, updated photometry and correction of GCN 19184
  91. GRB 160314B: Fermi GBM observation
  92. GRB 160314A: RATIR Optical and NIR Observations
  93. GRB 160314A: Mondy optical observations
  94. GRB 160313A: Swift/UVOT Upper Limits
  95. LIGO/Virgo G194575: EWE for NOWT follow-up of northern sky
  96. GRB 160314A: Optical observations from OSN
  97. GRB 160314A: Swift/UVOT Detection
  98. GRB 160228A: GROND afterglow confirmation and X-shooter host candidate redshift
  99. GRB 160314A: Enhanced Swift-XRT position
  100. GRB 160314A: ISON-Ussuriysk optical upper limit

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