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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"

27401 results found.

  1. GRB 100513A: Swift/UVOT upper limits
  2. GRB 100513A, RIMOTS optical upper limits
  3. GRB 100513A: Swift XRT refined analysis
  4. GRB 100513A: Swift-BAT refined analysis
  5. GRB 100513A: Enhanced Swift-XRT position
  6. GRB 100513A: SARA-N Upper Limit
  7. GRB 100513A: Swift detection of a burst
  8. GRB 100510A: Fermi GBM detection/observation
  9. GRB 100511A: Fermi GBM detection/observation
  10. GRB 100511A: Super-LOTIS early observations
  11. Swift-BAT trigger 421695 is likely not astrophysical
  12. GRB100504A: Optical upper limits at IAO
  13. GRB 100510A: MAXI/GSC detection
  14. GRB 100511A, RIMOTS optical upper limits
  15. Trigger 421695: Swift detection of a possible burst
  16. GRB100503A: Suzaku WAM observation of the prompt emission
  17. GRB 100508A: GROND Detection of the optical afterglow
  18. GRB 100508A: Swift-XRT Refined analysis
  19. GRB 100508A: Swift-BAT refined analysis
  20. GRB 100508A: Enhanced Swift-XRT position
  21. GRB100508A: Swift/UVOT Detection of the Afterglow
  22. GRB 100508A: ROTSE-III Optical Limits
  23. GRB 100508A: Swift detection of a burst
  24. GRB 100418A: Keck imaging
  25. GRB 100418A: RTT150 optical observations
  26. Swift-BAT refined analysis of trigger 421262
  27. An SGR-like burst from the magnetar 1E 1841-04.5 in Kes 73
  28. GRB 100504A: Swift/UVOT Observations
  29. GRB 100504A: Swift-XRT refined analysis
  30. GRB 100504A: Enhanced Swift-XRT position
  31. GRB 100504A: GROND Upper limits
  32. GRB 100504A: Swift-BAT refined analysis
  33. GRB 100504A: SARA-South Upper Limit
  34. GRB 100503A: Fermi GBM detection
  35. GRB 100504A: Swift detection of a burst
  36. INTEGRAL observations of Swift GRB trigger 421072
  37. GRB100423A : Suzaku WAM observation of the prompt emission
  38. Trigger 421072: Possible Swift detection of a GRB or transient
  39. GRB 100420A: Terskol optical upper limit
  40. GRB 100427A: Swift XRT and UVOT Upper Limits
  41. GRB 100427A: Fermi GBM detection
  42. GRB 100414A : EVLA Radio Detection
  43. GRB 100414A : WSRT Radio Detection
  44. GRB 100423A: CrAO optical observations
  45. GRB 100418A: Terskol optical observations
  46. GRB 100424A: CrAO optical observations
  47. GRB 100424A: NIR Afterglow Confirmation
  48. GRB 100425A: Swift XRT refined analysis
  49. GRB 100424A: Gemini/NIRI H-band observations
  50. GRB100425A: Swift/UVOT Upper Limits
  51. GRB 100424A: Swift/UVOT Upper Limits
  52. GRB 100424A: Liverpool Telescope Upper Limits
  53. GRB 100425A: Enhanced Swift-XRT position
  54. GRB 100425A: Swift-BAT refined analysis
  55. GRB 100425A: GROND afterglow observation
  56. GRB 100424A: Gemini/NIRI Candidate Afterglow
  57. GRB 100424A: D50 optical limits
  58. GRB 100425A: candidate optical afterglow from the VLT
  59. GRB100424A: MITSuME optical upper limits
  60. GRB100423A: MITSuME optical upper limits
  61. GRB 100424A : Lulin early z'-band upper limit
  62. GRB 100424A: GROND Upper Limits
  63. GRB 100424A: PAIRITEL NIR Upper Limits
  64. GRB 100424A: Swift-XRT refined analysis
  65. GRB 100425A: Swift detection of a burst
  66. GRB 100424A: NOT optical observations
  67. GRB 100424A, Swift-BAT refined analysis
  68. GRB 100424A: Enhanced Swift-XRT position
  69. GRB 100424A: Prompt enhanced Swift-XRT position.
  70. GRB 100424A: Swift detection of a burst
  71. GRB 100420A: GRT Optical Observation
  72. Swift Trigger 420256: D50 optical limits
  73. GRB 100423B: Fermi GBM detection
  74. GRB 100423A: Swift-BAT refined analysis
  75. Swift Trigger 420256: IAC80 R-band observations
  76. Swift Trigger 420256: BOOTES-2 observations
  77. Trigger 420256: Swift detection of a possible GRB
  78. GRB 100423A: GROND discovery of afterglow
  79. GRB 100418A: Continued PAIRITEL NIR Observations
  80. GRB100418A: REM possible afterglow detection
  81. GRB 100418A: Continuing Swift/UVOT Observations
  82. GRB100420A: MITSuME optical upper limits
  83. GRB 100414A: CFHT optical observations
  84. GRB 100420A: Swift/UVOT Upper Limits
  85. GRB 100420A: XRT refined analysis
  86. GRB 100420A: Enhanced Swift-XRT position
  87. GRB 100418A: SARA second epoch
  88. GRB 100420A: SARA Upper Limits
  89. GRB 100418A: optical observations
  90. GRB 100414A: Confirmation of the X-ray afterglow
  91. GRB 100418A: SMA submm detection
  92. GRB 100420A: Swift detection of a burst
  93. GRB 100418A PAIRITEL NIR Observations
  94. GRB 100418A: Swift/UVOT Observations
  95. GRB 100418A: Gemini-N redshift confirmation
  96. GRB 100418A: Swift-XRT Refined Analysis
  97. GRB100418A: VLT/X-shooter redshift and photometry
  98. GRB 100418A: SARA observations
  99. GRB 100418A: GROND observations; missing author list added
  100. GRB 100418A: GROND observations

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