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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"

27419 results found.

  1. IPN Triangulation of GRB 141104A (long/very bright)
  2. GRB 141102A possible precursor was another, known source
  3. Konus-Wind observation of GRB 141102A
  4. GRB 141022A: Skynet PROMPT-CTIO Observations
  5. GRB 141102A: Fermi-LAT detection
  6. GRB 141102A: Fermi GBM detection
  7. GRB 141102A found in ground analysis of BAT data
  8. GRB 141031B: RATIR Optical and NIR Observation
  9. GRB 141031B: Swift/UVOT Upper Limits
  10. GRB 141031B: Swift-XRT refined Analysis
  11. GRB 141031B: Bassano Bresciano Observatory upper limit
  12. GRB 141031B: Swift-BAT refined analysis
  13. GRB 141031A, Swift-BAT refined analysis
  14. GRB 141031A: Swift/UVOT Upper Limits
  15. GRB 141031B: TShAO optical upper limit
  16. GRB 141031A: Swift-XRT refined Analysis
  17. GRB 141031A: Skynet PROMPT-CTIO Observations
  18. GRB 141004A: Continued Late Time RATIR Optical and NIR Observations
  19. GRB 141031A: Fermi GBM detection
  20. GRB 141031B: MASTER early optical observations
  21. GRB 141031B: Swift detection of a burst
  22. GRB 141031A: GROND detection of a possible optical afterglow candidate
  23. GRB 141031A: Swift detection of a burst
  24. GRB 141029A: Nanshan optical upper limit
  25. GRB 141028A: SAO RAS Zeiss-1000 photometry
  26. GRB 140509A: GROND afterglow detection
  27. GRB 141028A: Continued RATIR Observations
  28. GRB 141028A: Swift/UVOT followup observations
  29. GRB 141029B: Fermi GBM detection
  30. GRB 141028A: Swift-XRT observations
  31. GRB 141028A: LCOGTN observations
  32. GRB141028A: Gemini-North redshift
  33. GRB 141028A: RATIR Optical and NIR Observations
  34. GRB 141028A: Swift/UVOT Detection
  35. GRB 141028A: Swift/XRT detection of the X-ray afterglow
  36. GRB 141028A: GROND Afterglow confirmation (MASTER source)
  37. GRB 141028A: Fermi GBM detection
  38. GRB 141026A: Continued RATIR Optical and NIR Observations
  39. GRB 141028A: Fermi-LAT detection
  40. GRB 141026A: Skynet PROMPT-CTIO/Yerkes-41 Observations
  41. GRB 141026A: SAO RAS Zeiss-1000 observations
  42. GRB 141026A: Continued RATIR Optical and NIR Observations
  43. GRB 141026A: Swift/UVOT Upper Limits
  44. GRB 141004A: Continued RATIR Late Time Optical and NIR Observations
  45. GRB 141026A: Continued RATIR Optical and NIR Observations, Afterglow Detection
  46. GRB 141026A: Swift-XRT refined Analysis
  47. GRB 141026A: Swift-BAT refined analysis
  48. Fermi Gamma-ray Burst Monitor trigger 141026452 is not a GRB
  49. GRB 141026A: MASTER early optical observations
  50. GRB141026A: Deep P200 optical imaging
  51. GRB 141026A: GROND observations
  52. GRB 141026A: RATIR Optical Observations
  53. GRB 141026A: P60 early observations
  54. GRB 141026A: Swift detection of a burst
  55. Fermi Gamma-ray Burst Monitor trigger 141025734 is not a GRB
  56. GRB141022A: Fermi GBM Detection
  57. GRB141022B: Fermi GBM Detection
  58. GRB 141022A: Swift/UVOT Upper Limits
  59. GRB 141022A: Swift-BAT refined analysis
  60. GRB 141022A: Swift-XRT refined Analysis
  61. GRB141015A iTelescope observation
  62. GRB 141022A: GROND Detection of a possible Optical Afterglow Candidate
  63. GRB 141022A: Swift detection of a burst
  64. GRB 141004A: RATIR Late Time Optical and NIR Observations
  65. GRB 141020A: Swift-BAT refined analysis
  66. GRB 141020A: Swift-XRT refined Analysis
  67. GRB 141020A: Swift/UVOT Detection
  68. Konus-Wind observation of GRB 141017A
  69. GRB 141020A: Swift detection of a burst with an optical counterpart
  70. GRB 141017A, Swift-BAT refined analysis
  71. GRB 141017A: GROND Afterglow Confirmation
  72. GRB 141015A: Swift-XRT afterglow confirmation and refined Analysis
  73. GRB 141017A: Swift/UVOT Detection
  74. GRB 141017A: Swift-XRT refined Analysis
  75. GRB 141017A: Zadko observatory - Gingin optical observations
  76. GRB 141017A: Swift detection of a burst
  77. GRB 141015A: Swift/UVOT Upper Limits
  78. GRB 141015A: Swift-BAT refined analysis
  79. GRB 141015A: LCO-McDonald observations
  80. GRB 141015A: RATIR Optical Upper Limits
  81. GRB 141015A: Super-LOTIS early observations
  82. GRB 141015A: Swift/XRT localization
  83. GRB 141015A: Swift detection of a burst
  84. Fermi Gamma-ray Burst Monitor trigger 141014781 is not a GRB
  85. IPN Triangulation of GRB 141011A (short/hard)
  86. GRB 141011A: Fermi GBM detection
  87. Trigger 614903: Swift detection of IGR J17544-2619
  88. GRB 141005A: iTelescope.Net T21 Optical Observation
  89. GRB 141005A: Additional P60 imaging and afterglow confirmation
  90. GRB 141004A: Fermi GBM observation
  91. GRB 141004A: GROND observations
  92. GRB 141005A: GROND observations
  93. Konus-Wind observation of GRB 141005A
  94. GRB 141004A: Swift-XRT refined Analysis
  95. GRB 141005A: Swift-XRT refined Analysis
  96. GRB 141005A: Swift/UVOT Upper Limits
  97. GRB 141005A: Swift-BAT refined analysis
  98. GRB 141004A: Swift-BAT refined analysis
  99. GRB141004A: NOT imaging and spectroscopy
  100. GRB 141004A: Swift/UVOT Detection

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