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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"

19093 results found.

  1. GRB 141109A: Enhanced Swift-XRT position
  2. GRB 141109A: CQUEAN Detection at 0.85 - 1.05 micron
  3. GRB 141109A: GROND afterglow observation
  4. GRB 141109A: REM NIR candidate afterglow
  5. GRB 141109B: Swift detection of a burst
  6. GRB 141109A: Swift detection of a burst
  7. GRB 141028A: Mondy optical observations
  8. GRB 141026A: CrAO optical observation
  9. GRB
  10. GRB 141026A: Gemini-North optical and NIR imaging
  11. GRB 141028A: TShAO optical observation
  12. GRB 141031B: TShAO optical observations
  13. GRB 141017A: Skynet PROMPT-CTIO/SSO Observations
  14. IPN Triangulation of GRB 141104A (long/very bright)
  15. GRB 141022A: Skynet PROMPT-CTIO Observations
  16. GRB 141026A: VLA observations
  17. GRB 141031B: RATIR Optical and NIR Observation
  18. GRB 141031B: Swift/UVOT Upper Limits
  19. GRB 141031B: Bassano Bresciano Observatory upper limit
  20. GRB 141031B: NOT optical observations
  21. GRB 141031B: MITSuME Ishigakijima upper limits
  22. GRB 141031B: Enhanced Swift-XRT position
  23. GRB 141031A: Swift/UVOT Upper Limits
  24. GRB 141031B: TShAO optical upper limit
  25. GRB 141031B: 1.23m CAHA I-band observations
  26. GRB 141031A: Skynet PROMPT-CTIO Observations
  27. GRB 141004A: Continued Late Time RATIR Optical and NIR Observations
  28. GRB 141031A: VLT/X-shooter optical observations
  29. GRB 141031B: Nanshan optical upper limit
  30. GRB 141031B: Swift detection of a burst
  31. GRB 141031A: Enhanced Swift-XRT position
  32. GRB 141031A: GROND detection of a possible optical afterglow candidate
  33. GRB 141031A: Swift detection of a burst
  34. GRB 141029A: Nanshan optical upper limit
  35. GRB 141028A: SAO RAS Zeiss-1000 photometry
  36. GRB 140509A: GROND afterglow detection
  37. GRB 141028A: Continued RATIR Observations
  38. GRB 141028A: Swift/UVOT followup observations
  39. GRB 141028A: Swift-XRT observations
  40. GRB 141028A: LCOGTN observations
  41. GRB141028A: Gemini-North redshift
  42. GRB 141028A: RATIR Optical and NIR Observations
  43. GRB 141028A: Swift/UVOT Detection
  44. GRB 141028A: GROND Afterglow confirmation (MASTER source)
  45. GRB 141020A: Continued Mondy Observations, optical upper limit
  46. GRB 141026A: Continued RATIR Optical and NIR Observations
  47. GRB 141026A: Skynet PROMPT-CTIO/Yerkes-41 Observations
  48. GRB 141026A: SAO RAS Zeiss-1000 observations
  49. GRB 141026A: Continued RATIR Optical and NIR Observations
  50. GRB 141026A: Swift/UVOT Upper Limits
  51. GRB 141004A: Continued RATIR Late Time Optical and NIR Observations
  52. GRB 141026A: Continued RATIR Optical and NIR Observations, Afterglow Detection
  53. GRB 141026A: Enhanced Swift-XRT position
  54. GRB 141026A: 1.23m CAHA I-band observations
  55. GRB 141026A: GROND observations
  56. GRB 141026A: RATIR Optical Observations
  57. GRB 141026A: P60 early observations
  58. GRB 141026A: Swift detection of a burst
  59. GRB 141020A: AAO optical upper limit
  60. GRB 141020A: Khureltogot optical upper limit
  61. GRB 141022A: Swift/UVOT Upper Limits
  62. GRB 141020A: Mondy optical observations
  63. GRB 141022A: Swift-XRT refined Analysis
  64. GRB141015A iTelescope observation
  65. GRB 141022A: GROND Detection of a possible Optical Afterglow Candidate
  66. GRB 141022A: Swift detection of a burst
  67. GRB 141004A: RATIR Late Time Optical and NIR Observations
  68. GRB 141020A: Swift-BAT refined analysis
  69. GRB 141020A: Swift/UVOT Detection
  70. GRB 141020A: Enhanced Swift-XRT position
  71. GRB 141020A: Swift detection of a burst with an optical counterpart
  72. GRB 141017A: GROND Afterglow Confirmation
  73. GRB 141017A: Swift/UVOT Detection
  74. GRB 141015A: MITSuME Akeno upper limits
  75. GRB 141017A: Enhanced Swift-XRT position
  76. GRB 141017A: Zadko observatory - Gingin optical observations
  77. GRB 141017A: Swift detection of a burst
  78. GRB 141015A: Swift/UVOT Upper Limits
  79. GRB 141015A: MITSuME Okayama upper limits
  80. GRB 141015A: RATIR Optical Upper Limits
  81. GRB 141015A: Enhanced Swift-XRT position
  82. GRB 141015A: Super-LOTIS early observations
  83. GRB 141015A: ISON-NM early optical observations
  84. GRB 141015A: Swift/XRT localization
  85. IPN Triangulation of GRB 141011A (short/hard)
  86. Trigger 614903: Swift detection of IGR J17544-2619
  87. GRB 141005A: iTelescope.Net T21 Optical Observation
  88. GRB 141005A: Additional P60 imaging and afterglow confirmation
  89. GRB 141004A: GROND observations
  90. GRB 141005A: GROND observations
  91. GRB 141005A: Swift/UVOT Upper Limits
  92. GRB141004A: NOT imaging and spectroscopy
  93. GRB 141004A: Swift/UVOT Detection
  94. GRB 141005A: Fermi GBM Detection
  95. GRB 141005A: Enhanced Swift-XRT position
  96. GRB 141004A: RATIR Optical Observations
  97. GRB 141004A: Monte Agliale Observatory optical observations
  98. GRB 141005A: RATIR Optical Observations
  99. GRB 141005A: P60 probable afterglow deteaction
  100. GRB 141004A: Enhanced Swift-XRT position

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