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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"
  1. GRB 080725: Swift detection of a burst
  2. ATCA radio upper limit on GRB 080723B
  3. GRB 080723A: Swift/UVOT Upper Limits
  4. VLA radio upper limit on GRB 080721
  5. GRB 080723B - correction to flux conversion factor
  6. GRB 080723B - Swift-XRT refined analysis
  7. GRB 080723B - Swift-XRT position
  8. GRB 080723, Swift-BAT refined analysis
  9. GRB 080723B: AGILE GRID and MCAL results
  10. GRB 080723B : Planned XMM-Newton observation
  11. GRB 080723A: Swift-XRT refined analysis
  12. GRB 080723B: Detection and Localization by SuperAGILE
  13. GRB 080723B : a long GRB detected with INTEGRAL
  14. GRB 080723: Enhanced Swift-XRT position
  15. GRB 080723: Swift detection of a burst
  16. GRB 080721 : Lulin 2nd optical follow-ups
  17. GRB 080721: OA fading and redshift
  18. TNG/DOLORES redshift for GRB080721
  19. GRB 080721: UVOT Follow-Up Observations
  20. Konus-Wind observation of GRB 080721
  21. GRB 080721: Swift-XRT refined analysis
  22. GRB 080721: Enhanced Swift-XRT position
  23. GRB 080721, Swift-BAT refined analysis
  24. GRB 080721: Swift/UVOT Photometric Redshift
  25. GRB 080721 : Lulin Optical follow-ups
  26. GRB 080721: Swift-XRT correct position
  27. GRB 080721: Swift detection of a burst with a bright optical counterpart.
  28. Retraction of Swift Trigger 317393
  29. Trigger 317393: Swift detection of a possible GRB
  30. Trigger 317205: Swift detection of an outburst from XTE J1701-407
  31. GRB 080714: GROND confirmation of the optical/NIR afterglow
  32. Konus-Wind observation of GRB 080714
  33. GRB 080714: Swift/UVOT Detection of an Optical Afterglow
  34. GRB 080714: Swift-XRT refined analysis
  35. GRB 080714: Enhanced Swift-XRT position
  36. GRB 080714: Swift-BAT refined analysis
  37. GRB 080714: Swift detection of a burst
  38. GRB 080702A: optical upper limit
  39. GRB 080603A: CrAO optical observations
  40. GRB 080603B: optical observations in MAO
  41. GRB 080603B: optical observations in CrAO
  42. GRB 080710: Optical observation with MITSuME Okayama
  43. GRB 080710: TLS observations, steepening afterglow decay
  44. GRB 080702B: Swift XRT confirmation of the afterglow
  45. GRB 080710: Lick IR detection
  46. GRB 080710, Swift-BAT refined analysis
  47. GRB 0800707: optical observations
  48. GRB 080710: Rapid PROMPT Observations
  49. GRB 080710: Swift-XRT refined analysis
  50. GRB080710: Swift/UVOT observations
  51. GRB 080710: Enhanced Swift-XRT position
  52. GRB 080710: Faulkes Telescope North observations
  53. GRB 080710: Gemini spectroscopy and probable redshift
  54. UVOT white band observations of GRB080710
  55. GRB 080710: REM afterglow confirmation & brightening
  56. GRB 080710: KAIT OA candidate
  57. GRB 080710: Swift XRT position
  58. GRB 080710: Swift detection of a burst
  59. GRB 080707: possible break in the X-rays
  60. New Swift-XRT GRB products available online.
  61. GRB 080707: GROND Confirmation of the Optical Afterglow
  62. UVOT observations of GRB080707
  63. GRB 080707, Swift-BAT refined analysis
  64. GRB 080707: Swift XRT refined analysis
  65. GRB 080707: Enhanced Swift-XRT position
  66. GRB 080707: VLT redshift
  67. GRB 080707: GROND Detection of the Optical Afterglow Candidate
  68. GRB 080707: Swift detection of a burst
  69. Refined analysis of Swift Trigger 316063, is IGR J08408-4503
  70. Trigger 316063: Swift detection of a transient
  71. GRB 080703: GROND Upper Limits
  72. GRB 080702B: GROND Upper Limits
  73. GRB 080703: Swift-XRT refined analysis
  74. GRB 080703: UVOT Follow-Up Observation
  75. GRB 080703: VLT observations of the afterglow
  76. GRB 080703: Enhanced Swift-XRT position
  77. GRB 080703, Swift-BAT refined analysis
  78. GRB 080702B Swift-BAT refined analysis
  79. GRB 080703: Swift detection of a burst with optical afterglow
  80. GRB 080703A: ROTSE-III Detection of Optical Counterpart
  81. No radio detection from the short GRB 080702A
  82. GRB 080702b: LCO optical observations
  83. Swift/UVOT observation of GRB080702A
  84. GRB 080702B: Swift XRT and UVOT observations
  85. GRB 080625: Suzaku WAM observation of the prompt emission
  86. GRB 080702A: MITSuME Akeno optical upper limits
  87. GRB 080701A: Early RAPTOR optical limits
  88. Swift Trigger 315630: Swift/UVOT Upper Limits
  89. GRB 080702A, Swift-BAT refined analysis
  90. GRB 080702A: Swift-XRT Team refined analysis
  91. GRB 080702B : Burst detected in BAT during Swift slew
  92. GRB 080702A: Enhanced Swift-XRT position
  93. Swift Trigger 315630: TLS R-band observation
  94. Swift Trigger 315630: Probably not a GRB
  95. GRB 080702: Swift detection of a short burst
  96. GRB 080701: Swift-XRT refined analysis
  97. GRB 080701A, VATT optical upper limit
  98. TLS I-Band Observation of GRB 080701A
  99. GRB 080701A: Swift/UVOT Upper Limits
  100. GRB 080701A: Early Super-LOTIS Observations

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