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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"

28056 results found.

  1. GRB 100606A: Swift-BAT refined analysis
  2. GRB 100606A: Enhanced Swift-XRT position
  3. Swift Trigger 424040 is not a GRB
  4. GRB 100606A: Swift detection of a burst
  5. Swift detection of outburst from the SFXT IGR J18410-0535
  6. GRB 100111A: Maidanak optical observations
  7. GRB 100418A: Maidanak optical observations
  8. GRB 100513A: CrAO optical observations
  9. GRB 100514A: CrAO optical observations
  10. GRB 100526A: optical upper limit
  11. GRB 100528A: Faulkes Telescope North Detection
  12. GRB 100528A: GROND detection in all bands
  13. GRB 100528A: NOT optical observation
  14. Swift UVOT and UVOT-enhanced XRT position for GRB 100528A
  15. GRB100526B: GROND Upper limits
  16. GRB 100528A: SuperAGILE Localization of a Long GRB
  17. GRB 100526B: Swift-XRT confirmation of fading afterglow
  18. GRB 100526B: Swift/UVOT Upper Limits
  19. GRB 100526A: Swift/UVOT Upper Limits
  20. GRB 100526A: Gemini/NIRI infrared afterglow candidate
  21. GRB 100526A: NOT optical upper limit
  22. GRB 100526A: Swift XRT refined analysis
  23. GRB 100526B: Swift-BAT refined analysis
  24. GRB 100526B: Swift XRT/UVOT observations
  25. GRB 100526A: Swift-BAT refined analysis
  26. GRB 100526A: Enhanced Swift-XRT position
  27. GRB 100526A: MASTER-Net optical alert observations
  28. GRB 100526A: Swift detection of a burst
  29. GRB100522A: Suzaku WAM observation of the prompt emission
  30. GRB 100418A: Subaru late-time optical imaging and spectroscopy
  31. GRB 100522A: GROND observations, upper limits
  32. GRB 100522A: Fermi GBM observation
  33. GRB 100522A: Swift XRT refined analysis
  34. GRB 100522A, Swift-BAT refined analysis
  35. GRB 100522A: Enhanced Swift-XRT position
  36. GRB 100522A: NIR observations from CAHA
  37. GRB 100522A: Swift detection of a burst
  38. GRB 100418A: CrAO optical observations
  39. GRB 100518A: GROND afterglow observation and photo-z
  40. GRB 100518A: Swift-XRT refined analysis
  41. GRB 100518A: optical afterglow decay
  42. GRB 100518A: BOOTES-3 optical observations
  43. Update to the configuration of the Fermi-LAT onboard GRB search
  44. GRB 100518A: Swift target of opportunity observation of the INTEGRAL burst
  45. GRB 100513A: MITSuME Akeno Optical Observation
  46. GRB 100518A: a long GRB detected with INTEGRAL
  47. Swift Trigger 422437 is probably not a GRB
  48. GRB 100517A: MASTER-Net wide field camera prompt optical observations
  49. GRB 100514A: optical afterglow confirmation
  50. GRB 100514A: Swift/UVOT Observations
  51. GRB 100514A: YNAO-GMG observations
  52. GRB 100514A: Swift XRT refined analysis
  53. GRB 100514A: Enhanced Swift-XRT position
  54. GRB 100514A: Swift-BAT refined analysis
  55. GRB 100514A: Swift detection of a burst
  56. GRB 100513A: Swift/UVOT upper limits
  57. GRB 100513A, RIMOTS optical upper limits
  58. GRB 100513A: Swift XRT refined analysis
  59. GRB 100513A: Swift-BAT refined analysis
  60. GRB 100513A: Enhanced Swift-XRT position
  61. GRB 100513A: SARA-N Upper Limit
  62. GRB 100513A: Swift detection of a burst
  63. GRB 100510A: Fermi GBM detection/observation
  64. GRB 100511A: Fermi GBM detection/observation
  65. GRB 100511A: Super-LOTIS early observations
  66. Swift-BAT trigger 421695 is likely not astrophysical
  67. GRB100504A: Optical upper limits at IAO
  68. GRB 100510A: MAXI/GSC detection
  69. GRB 100511A, RIMOTS optical upper limits
  70. Trigger 421695: Swift detection of a possible burst
  71. GRB100503A: Suzaku WAM observation of the prompt emission
  72. GRB 100508A: GROND Detection of the optical afterglow
  73. GRB 100508A: Swift-XRT Refined analysis
  74. GRB 100508A: Swift-BAT refined analysis
  75. GRB 100508A: Enhanced Swift-XRT position
  76. GRB100508A: Swift/UVOT Detection of the Afterglow
  77. GRB 100508A: ROTSE-III Optical Limits
  78. GRB 100508A: Swift detection of a burst
  79. GRB 100418A: Keck imaging
  80. GRB 100418A: RTT150 optical observations
  81. Swift-BAT refined analysis of trigger 421262
  82. An SGR-like burst from the magnetar 1E 1841-04.5 in Kes 73
  83. GRB 100504A: Swift/UVOT Observations
  84. GRB 100504A: Swift-XRT refined analysis
  85. GRB 100504A: Enhanced Swift-XRT position
  86. GRB 100504A: GROND Upper limits
  87. GRB 100504A: Swift-BAT refined analysis
  88. GRB 100504A: SARA-South Upper Limit
  89. GRB 100503A: Fermi GBM detection
  90. GRB 100504A: Swift detection of a burst
  91. INTEGRAL observations of Swift GRB trigger 421072
  92. GRB100423A : Suzaku WAM observation of the prompt emission
  93. Trigger 421072: Possible Swift detection of a GRB or transient
  94. GRB 100420A: Terskol optical upper limit
  95. GRB 100427A: Swift XRT and UVOT Upper Limits
  96. GRB 100427A: Fermi GBM detection
  97. GRB 100414A : EVLA Radio Detection
  98. GRB 100414A : WSRT Radio Detection
  99. GRB 100423A: CrAO optical observations
  100. GRB 100418A: Terskol optical observations

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