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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"

20391 results found.

  1. GRB 100621A: Swift detection of a burst
  2. GRB 100606A: Optical Limits
  3. GRB 100619A: Swift/UVOT Upper Limits
  4. GRB 100619A: Enhanced Swift-XRT position
  5. GRB 100619A: Swift detection of a burst
  6. GRB 100614A: Gemini/NIRI Observations
  7. GRB 100615A: Gemini/NIRI Observations
  8. XRF 100616a : MAXI/GSC detection of a probable XRF
  9. GRB 100615A: Swift/UVOT Upper Limits
  10. GRB 100614A: Swift/UVOT Upper Limits
  11. GRB 100614A: NOT optical upper limits
  12. GRB 100614A: Enhanced Swift-XRT position
  13. GRB 100615A: Enhanced Swift-XRT position
  14. GRB 100615A: PAIRITEL NIR Upper Limits
  15. GRB 100615A: NTT/Ultracam imaging
  16. GRB 100615A: Swift detection of a burst
  17. GRB 100614A: Swift detection of a burst
  18. GRB 100606A: GROND observations
  19. Trigger 424161: Swift/BAT trigger on XTE J1946+274/GRO J1944+26
  20. Radio detection of GRB100418a with ATCA
  21. GRB 100606A: Swift/UVOT Upper Limits
  22. GRB 100606A Swift-XRT refined analysis
  23. GRB 100606A: Enhanced Swift-XRT position
  24. Swift Trigger 424040 is not a GRB
  25. GRB 100606A: Swift detection of a burst
  26. Swift detection of outburst from the SFXT IGR J18410-0535
  27. GRB 100111A: Maidanak optical observations
  28. GRB 100418A: Maidanak optical observations
  29. GRB 100513A: CrAO optical observations
  30. GRB 100514A: CrAO optical observations
  31. GRB 100526A: optical upper limit
  32. GRB 100528A: Faulkes Telescope North Detection
  33. GRB 100528A: GROND detection in all bands
  34. GRB 100528A: NOT optical observation
  35. Swift UVOT and UVOT-enhanced XRT position for GRB 100528A
  36. GRB100526B: GROND Upper limits
  37. GRB 100526B: Swift/UVOT Upper Limits
  38. GRB 100526A: Swift/UVOT Upper Limits
  39. GRB 100526A: Gemini/NIRI infrared afterglow candidate
  40. GRB 100526A: NOT optical upper limit
  41. GRB 100526B: Swift XRT/UVOT observations
  42. GRB 100526A: Enhanced Swift-XRT position
  43. GRB 100526A: MASTER-Net optical alert observations
  44. GRB 100526A: Swift detection of a burst
  45. GRB 100418A: Subaru late-time optical imaging and spectroscopy
  46. GRB 100522A: Enhanced Swift-XRT position
  47. GRB 100522A: NIR observations from CAHA
  48. GRB 100522A: Swift detection of a burst
  49. GRB 100418A: CrAO optical observations
  50. GRB 100518A: GROND afterglow observation and photo-z
  51. GRB 100518A: Swift-XRT refined analysis
  52. GRB 100518A: BOOTES-3 optical observations
  53. GRB 100518A: Swift target of opportunity observation of the INTEGRAL burst
  54. GRB 100513A: MITSuME Akeno Optical Observation
  55. Swift Trigger 422437 is probably not a GRB
  56. GRB 100517A: MASTER-Net wide field camera prompt optical observations
  57. GRB 100514A: optical afterglow confirmation
  58. GRB 100514A: Swift/UVOT Observations
  59. GRB 100514A: YNAO-GMG observations
  60. GRB 100514A: Enhanced Swift-XRT position
  61. GRB 100514A: Swift detection of a burst
  62. GRB 100513A: Swift/UVOT upper limits
  63. GRB 100513A, RIMOTS optical upper limits
  64. GRB 100513A: Enhanced Swift-XRT position
  65. GRB 100513A: SARA-N Upper Limit
  66. GRB 100513A: Swift detection of a burst
  67. GRB 100511A: Fermi GBM detection/observation
  68. GRB 100511A: Super-LOTIS early observations
  69. GRB100504A: Optical upper limits at IAO
  70. GRB 100510A: MAXI/GSC detection
  71. GRB 100511A, RIMOTS optical upper limits
  72. Trigger 421695: Swift detection of a possible burst
  73. GRB 100508A: GROND Detection of the optical afterglow
  74. GRB 100508A: Enhanced Swift-XRT position
  75. GRB100508A: Swift/UVOT Detection of the Afterglow
  76. GRB 100508A: ROTSE-III Optical Limits
  77. GRB 100508A: Swift detection of a burst
  78. GRB 100418A: Keck imaging
  79. GRB 100418A: RTT150 optical observations
  80. An SGR-like burst from the magnetar 1E 1841-04.5 in Kes 73
  81. GRB 100504A: Swift/UVOT Observations
  82. GRB 100504A: Enhanced Swift-XRT position
  83. GRB 100504A: GROND Upper limits
  84. GRB 100504A: SARA-South Upper Limit
  85. GRB 100503A: Fermi GBM detection
  86. GRB 100504A: UVOT-enhanced XRT position
  87. GRB 100504A: Swift detection of a burst
  88. INTEGRAL observations of Swift GRB trigger 421072
  89. Trigger 421072: Possible Swift detection of a GRB or transient
  90. GRB 100420A: Terskol optical upper limit
  91. GRB 100427A: Swift XRT and UVOT Upper Limits
  92. GRB 100414A : EVLA Radio Detection
  93. GRB 100414A : WSRT Radio Detection
  94. GRB 100423A: CrAO optical observations
  95. GRB 100418A: Terskol optical observations
  96. GRB 100424A: CrAO optical observations
  97. GRB 100424A: NIR Afterglow Confirmation
  98. GRB 100424A: Gemini/NIRI H-band observations
  99. GRB100425A: Swift/UVOT Upper Limits
  100. GRB 100424A: Swift/UVOT Upper Limits

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