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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"

28059 results found.

  1. GRB 131014A: GROND observations
  2. GRB 131014A: RATIR Optical/NIR Afterglow Confirmation
  3. Fermi GBM data availability during U.S. government shutdown
  4. GRB 131014A: Swift-XRT refined Analysis
  5. GRB 131011A: Swift/UVOT Upper Limits
  6. GRB 131014A: Swift/UVOT Upper Limits
  7. GRB 131014A: RATIR Optical and NIR Observations
  8. GRB 131014A: Enhanced XRT position
  9. GRB 131014A: NOT afterglow candidate
  10. GRB 131014A: Nanshan optical observations
  11. GRB 131014A: Fermi-LAT detection
  12. GRB 131014A: Fermi GBM detection
  13. Swift-XRT detection of iPTF 13dsw/Fermi403206457
  14. GRB 131011A: GROND afterglow observations
  15. Fermi403206457: continued P60 observations and fading behavior
  16. Fermi403206457: Weihai optical upper limit
  17. Trigger 574266 is not a Swift detection of a known source
  18. GRB 130831A: Continued RATIR Optical and NIR Observations
  19. GRB 131004A: Skynet PROMPT/DSO-14 upper limits
  20. GRB 131004A, Swift-BAT refined analysis
  21. GRB 131004A: Swift/UVOT Detection
  22. GRB 131004A: RATIR Optical and NIR Upper Limits
  23. GRB 131004A: Swift-XRT refined Analysis
  24. GRB 131004A: GROND observations of the afterglow
  25. GRB 131004A: Enhanced Swift-XRT position
  26. GRB 131004A: Liverpool Telescope optical afterglow observations
  27. GRB 131004A: TNG optical afterglow confirmation
  28. GRB 131004A: optical afterglow from the NOT
  29. GRB 131004A: Swift detection of a burst (may be short)
  30. GRB 131002A, Swift-BAT refined analysis
  31. GRB 130925A/Sw J0244-2609: mm observations at PdBI
  32. GRB 131002B, Swift-BAT refined analysis
  33. GRB 131002B: GROND upper limits
  34. GRB 131002B: Swift-XRT Refined Analysis
  35. GRB 131002B: Swift/UVOT Upper Limits
  36. GRB 131002A: Swift/UVOT Detection
  37. GRB 131001A, Swift-BAT refined analysis
  38. GRB 131002A: Swift-XRT refined Analysis
  39. GRB 131002B: Enhanced Swift-XRT position
  40. Swift J1242.9-3530, Swift-BAT refined analysis
  41. GRB 131001A: Swift UVOT and XRT Upper Limits
  42. GRB 131002A: Enhanced Swift-XRT position
  43. NuSTAR observations of GRB 130925A
  44. GRB 131002B: Swift detection of a burst
  45. GRB 131002A: Swift detection of a burst
  46. GRB 131002A: Faulkes Telescope North optical afterglow
  47. US Government shutdown may impact GRB operation of GCN
  48. GRB 130929A: Swift/UVOT Upper Limits
  49. GRB 130831A: Continued RATIR Optical and NIR Observations
  50. GRB 130929A: Swift-XRT refined Analysis
  51. GRB 130929A, Swift-BAT refined analysis
  52. GRB 130929A: Enhanced Swift-XRT position
  53. GRB 130929A: TAROT La Silla observatory optical observations
  54. GRB 130929A: Swift detection of a burst
  55. Fermi LAT Upper Limits on GRB 130925A
  56. GRB 130925A: Swift/UVOT Upper Limits
  57. GRB 130925A: optical upper limit
  58. GRB 130925A: Continued RATIR Optical and NIR Observations
  59. Konus-Wind observation of GRB 130925A
  60. Observation of possible GRB/TDE 130925A by INTEGRAL/SPI-ACS: three activity episodes
  61. GRB 130925A: RATIR Optical and NIR Observations
  62. GRB 130925A Swift-BAT refined analysis
  63. Fermi GBM detection of GRB 130925A and a possible precursor
  64. GRB 130925A: Swift-XRT refined Analysis
  65. GRB 130925A: Initial Similarities to Swift J1644+57
  66. GRB 130925A: TAROT La Silla observatory optical observations
  67. GRB 130925A: Enhanced Swift-XRT position
  68. GRB 130925A: VLT/UVES observations
  69. GRB 130925A: MAXI/GSC detection
  70. GRB 130925A: GROND afterglow candidate
  71. GRB 130925A: Swift detection of a burst
  72. IPN Triangulation of SGR-like burst 130913 - probable association with SGR/AXP 1E1841-045
  73. GRB 130831A: RTT150 optical observations
  74. GRB 130831A: RATIR Confirmation of NIR/Optical Afterglow Flattening
  75. GRB 130903A: optical observations
  76. GRB 130907A: Maidanak optical observations
  77. GRB 130912A: AAO optical upper limit
  78. Fermi Trigger 401326696: MASTER prompt optical observations
  79. GRB 130919A: Skynet PROMPT-CTIO optical upper limits
  80. GRB 130919A, Swift-BAT refined analysis
  81. GRB 130913A detected in ground analysis of Swift-BAT data
  82. GRB 130912A: Swift/UVOT Upper Limits
  83. Fermi/GBM Detection of two SGR-like bursts possibly associated with SGR J1833-0832
  84. GRB 130912A: 5.8 GHz VLA upper limit
  85. GRB 130912A: RATIR Optical and NIR Upper Limits
  86. GRB 130907A: Continued RATIR Optical and NIR Observations
  87. GRB 130912A: P60 Observations
  88. GRB 130912A: Swift-XRT refined Analysis
  89. GRB 130907A: MASTER refined analysis
  90. GRB 130912A: Fermi GBM detection
  91. GRB 130912A: Skynet DSO-14/Yerkes-41/PROMPT-CTIO observations
  92. GRB 130912A: Enhanced Swift-XRT position
  93. GRB 130912A, Swift-BAT refined analysis
  94. GRB 130912A: REM optical/NIR upper limits
  95. GRB 130912A: GROND observations
  96. GRB 130912A: Swift detection of a short burst
  97. GRB 120419A: Swift XRT confirmation of the afterglow
  98. GRB 130907A: Continued RATIR Optical and NIR Observations
  99. GRB 130907A: RATIR Optical and NIR Observations
  100. GRB 130828A: Further Swift XRT observations

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