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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"

19548 results found.

  1. GRB 141121A: Continued RATIR Optical Observations
  2. GRB 141130A: Swift/UVOT Detection
  3. GRB 141130A: Enhanced Swift-XRT position
  4. GRB 141130A: Nanshan optical observations
  5. GRB 141130A: Mondy optical observations
  6. GRB 141130A: Swift detection of a burst with an optical counterpart
  7. GRB 141121A: Continued RATIR Optical Observations
  8. GRB 141121A: Mondy optical observations
  9. GRB 141121A: TSHAO optical observations
  10. GRB 141121A: Continued RATIR Optical Observations
  11. GRB 141121A: MITSuME Ishigakijima Optical Observation after 7 days
  12. GRB 141121A: Khureltogot optical observations
  13. GRB 141121A: Mondy optical observations
  14. GRB 141121A: RATIR Optical and NIR Observations
  15. IPN Triangulation of GRB 141125A (short/hard)
  16. GRB 141121A: three epochs of SAO RAS optical observations
  17. GRB 141121A: Continued RATIR Optical Observations
  18. GRB 141121A: TSHAO optical observations
  19. GRB 141121A: Continued Mondy optical observations
  20. GRB 141121A: Continued RATIR Optical Observations
  21. GRB 141121A: RATIR Optical Observations - Steeper Fading
  22. GRB 141121A: MITSuME Ishigakijima Optical Observation after 3 days
  23. GRB 141121A: RATIR Optical Observations - Fading Again
  24. GRB141124A: MASTER Detection of New Flare of QSO NVSS J075043+790917 During the Fermi Error Box inspection
  25. GRB 141121A: Mondy optical observations
  26. GRB 141121A: MITSuME Ishigakijima Optical Observation
  27. GRB 141121A: Continued RATIR Optical Observations - Rebrightening
  28. GRB 141121A: AAO optical observations
  29. GRB 141121A: MITSuME Akeno Optical observation
  30. GRB 141121A: Continued RATIR Optical Observations
  31. GRB 141121A: Swift/UVOT Detections
  32. GRB 141121A: RATIR Optical Observations
  33. GRB 141121A: Enhanced Swift-XRT position
  34. GRB 141118A: iPTF Optical Observations
  35. GRB 141121A: GROND Afterglow candidate
  36. GRB 141121A: Swift detection of a burst
  37. IPN Triangulation of GRB 141118A
  38. GRB 141104A: further Swift-XRT observations and afterglow candidate
  39. Swift Trigger 618673: probable noise event
  40. Trigger 618634: Swift detection of Vela X-1
  41. GRB 141109B: optical upper limits
  42. GRB 141015A: TAROT La Silla observatory optical observations
  43. GRB 141022A: TAROT La Silla observatory optical observations
  44. GRB 141031A: TAROT La Silla observatory optical observations
  45. GRB 141109A: TAROT La Silla observatory optical observations
  46. GRB 141109A: AAO optical observations
  47. Swift Trigger 618402: probable noise event
  48. GRB 141109A: Terskol photometry
  49. GRB 141109B: Swift/UVOT Upper Limits
  50. GRB 141109A: Swift/UVOT Detection
  51. GRB 141109A: NOT r-band observation
  52. GRB 141109B: MITSuME Akeno upper limits
  53. GRB 141109A: MITSuME Ishigakijima upper limits
  54. GRB 141109A: Swift-XRT refined Analysis
  55. GRB 141109B: Enhanced Swift-XRT position
  56. GRB 141109A: Enhanced Swift-XRT position
  57. GRB 141109A: CQUEAN Detection at 0.85 - 1.05 micron
  58. GRB 141109A: GROND afterglow observation
  59. GRB 141109A: REM NIR candidate afterglow
  60. GRB 141109B: Swift detection of a burst
  61. GRB 141109A: Swift detection of a burst
  62. GRB 141028A: Mondy optical observations
  63. GRB 141026A: CrAO optical observation
  64. GRB
  65. GRB 141026A: Gemini-North optical and NIR imaging
  66. GRB 141028A: TShAO optical observation
  67. GRB 141031B: TShAO optical observations
  68. GRB 141017A: Skynet PROMPT-CTIO/SSO Observations
  69. IPN Triangulation of GRB 141104A (long/very bright)
  70. GRB 141022A: Skynet PROMPT-CTIO Observations
  71. GRB 141026A: VLA observations
  72. GRB 141031B: RATIR Optical and NIR Observation
  73. GRB 141031B: Swift/UVOT Upper Limits
  74. GRB 141031B: Bassano Bresciano Observatory upper limit
  75. GRB 141031B: NOT optical observations
  76. GRB 141031B: MITSuME Ishigakijima upper limits
  77. GRB 141031B: Enhanced Swift-XRT position
  78. GRB 141031A: Swift/UVOT Upper Limits
  79. GRB 141031B: TShAO optical upper limit
  80. GRB 141031B: 1.23m CAHA I-band observations
  81. GRB 141031A: Skynet PROMPT-CTIO Observations
  82. GRB 141004A: Continued Late Time RATIR Optical and NIR Observations
  83. GRB 141031A: VLT/X-shooter optical observations
  84. GRB 141031B: Nanshan optical upper limit
  85. GRB 141031B: Swift detection of a burst
  86. GRB 141031A: Enhanced Swift-XRT position
  87. GRB 141031A: GROND detection of a possible optical afterglow candidate
  88. GRB 141031A: Swift detection of a burst
  89. GRB 141029A: Nanshan optical upper limit
  90. GRB 141028A: SAO RAS Zeiss-1000 photometry
  91. GRB 140509A: GROND afterglow detection
  92. GRB 141028A: Continued RATIR Observations
  93. GRB 141028A: Swift/UVOT followup observations
  94. GRB 141028A: Swift-XRT observations
  95. GRB 141028A: LCOGTN observations
  96. GRB141028A: Gemini-North redshift
  97. GRB 141028A: RATIR Optical and NIR Observations
  98. GRB 141028A: Swift/UVOT Detection
  99. GRB 141028A: GROND Afterglow confirmation (MASTER source)
  100. GRB 141020A: Continued Mondy Observations, optical upper limit

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