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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"

28094 results found.

  1. GRB 100902A: Swift-BAT refined analysis
  2. IPN Triangulation of the very bright GRB 100829A
  3. GRB 100902A: Swift XRT refined analysis
  4. GRB 100902A: Swift/UVOT Upper Limits
  5. GRB 100902A: optical observation at Mt.Terskol
  6. GRB 100901A: optical observation at Mt.Terskol
  7. GRB100901A: MITSuME Okayama Optical Observation at 1 day after the burst
  8. GRB 100902A: Enhanced Swift-XRT position
  9. GRB 100901A: TLS Observations: Break?
  10. GRB 100901A: ISON-NM optical observations
  11. GRB 100902A: Faulkes Telescope South observations
  12. GRB 100902A: Swift detection of a burst
  13. GRB 100901A: Vega telescope optical afterglow observation
  14. Swift/UVOT Observations of GRB100901A
  15. GRB 100901A: SARA-N observations
  16. GRB 100901A: THO optical observations
  17. GRB100901A: MITSuME Okayama Optical Observation
  18. GRB 100901A: Swift-XRT Team refined analysis
  19. GRB 100901A - NOT optical observation
  20. GRB 100901A: Swift-BAT refined analysis
  21. GRB 100901A: Enhanced Swift-XRT position
  22. GRB 100901A: Swift detection of a burst with an optical afterglow
  23. GRB 100829.9: MASTER Optical Limits
  24. GRB 100823A: optical upper limit
  25. GRB 100814A: Maidanak optical observations
  26. GRB 100823A: optical observations
  27. GRB 100725B: Mondy optical upper limit
  28. GRB 100725B: Maidanak optical upper limit
  29. GRB100807A: R band observations
  30. GRB 100823A: Swift XRT refined analysis
  31. GRB 100823A - second epoch WHT observations
  32. GRB 100823A: TNG NIR observations
  33. GRB 100823A: Swift/UVOT Upper Limits
  34. GRB 100823A: WHT observations
  35. GRB 100823A: Swift-BAT refined analysis
  36. GRB 100823A: Enhanced Swift-XRT position
  37. GRB 100823A: Swift detection of a burst
  38. GRB 100814A: Suzaku WAM observation of the prompt emission
  39. GRB 100814B: Fermi GBM detection
  40. GRB 100814A: optical observations
  41. GRB100816A: MITSuME optical upper limits
  42. GRB 100814A: NOT optical observations
  43. GRB 100816A: NOT optical observations
  44. GRB 100814A : Lulin optical observation
  45. GRB 100816A : Lulin r'-band observation
  46. GRB 100816A: Swift UVOT Observations
  47. GRB100816A Swift-XRT refined analysis
  48. GRB 100816A: Swift-BAT spectral lag results
  49. GRB 100816A: 1.23m CAHA optical observations
  50. GRB 100816A, Swift-BAT refined analysis
  51. GRB 100816A: Enhanced Swift-XRT position
  52. GRB 100816A: Gemini-N imaging
  53. GRB 100816A: TAROT Calern observatory optical detection
  54. GRB 100816A: MASTER Optical Limits
  55. GRB100816A: TNG optical afterglow confirmation.
  56. GRB 100816A: Swift detection of a possibly short burst with optical afterglow
  57. GRB 100814A: Fermi GBM observation
  58. GRB 100814A: Submm observations from APEX
  59. GRB 100814A: Swift-XRT refined analysis
  60. Swift/UVOT observations of GRB100814A
  61. GRB 100814A, Swift-BAT refined analysis
  62. GRB 100814A: Enhanced Swift-XRT position
  63. GRB 100814A: GROND Detection of the Optical/NIR Afterglow
  64. GRB 100814A: Swift UVOT observations of the optical afterglow
  65. GRB 100814A: Swift detection of a burst with an optical afterglow
  66. GRB 100814A: ROTSE-III Detection of Optical Counterpart
  67. GRB 100805A: the 4-th epoch of SAO RAS optical observations
  68. GRB 100805A: optical observation in CrAO (correction to the GCN 11077 and second epoch)
  69. GRB 100802A: further NOT observation
  70. GRB 100805A: Swift/UVOT Observations of a Possible Late-Time Brightening
  71. GRB 100807A: P200 Infrared Observations
  72. GRB 100805A: the 3-rd epoch of SAO RAS optical observations
  73. GRB100807A: optical observation in CrAO
  74. GRB 100805A: optical observation in CrAO
  75. GRB 100805A: 2-nd epoch of SAO RAS optical observations
  76. GRB100807A: MITSuME optical upper limits
  77. GRB 100807A: Swift XRT refined analysis
  78. GRB 100807A: P60 Optical Afterglow Discovery
  79. GRB 100807A: Swift/UVOT Upper Limits
  80. GRB 100805A: SAO RAS optical observations
  81. GRB 100807A: Enhanced Swift-XRT position
  82. GRB 100807A: Swift-BAT refined analysis
  83. GRB 100807A: Swift detection of a burst
  84. GRB 100805A: IAC80 and 1.5m OSN optical observations
  85. GRB 100805A: Early RAPTOR Observations
  86. GRB 100805A: Swift/UVOT Observations of the Optical Afterglow
  87. GRB 100802A: WIYN observations
  88. GRB 100805A: IAC80 BVR-band observations
  89. GRB 100805A: Swift-BAT refined analysis
  90. GRB 100805A: Swift-XRT Refined Analysis
  91. GRB 100805A: GRAS 002 optical observations
  92. Trigger 430975: Swift detection of a possible burst
  93. GRB 100805A: I-band detection from 1.23m CAHA telescope.
  94. GRB 100805A: Enhanced Swift-XRT position
  95. GRB 100805A: Further P60 Monitoring
  96. GRB 100805A: P60 Optical Afterglow Candidate
  97. GRB 100805A: Swift detection of a burst with an optical counterpart
  98. GRB 100802A: Fermi GBM observation
  99. GRB 100728B: optical photometry of ISON-NM
  100. GRB 100713A: second epoch Maidanak optical observation

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