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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"

27481 results found.

  1. GRB 080721: Swift-XRT correct position
  2. GRB 080721: Swift detection of a burst with a bright optical counterpart.
  3. Retraction of Swift Trigger 317393
  4. Trigger 317393: Swift detection of a possible GRB
  5. Trigger 317205: Swift detection of an outburst from XTE J1701-407
  6. GRB 080714: GROND confirmation of the optical/NIR afterglow
  7. GRB 080714: Swift/UVOT Detection of an Optical Afterglow
  8. GRB 080714: Swift-XRT refined analysis
  9. GRB 080714: Enhanced Swift-XRT position
  10. GRB 080714: Swift detection of a burst
  11. GRB 080702A: optical upper limit
  12. GRB 080603A: CrAO optical observations
  13. GRB 080603B: optical observations in MAO
  14. GRB 080603B: optical observations in CrAO
  15. GRB 080710: Optical observation with MITSuME Okayama
  16. GRB 080710: TLS observations, steepening afterglow decay
  17. GRB 080702B: Swift XRT confirmation of the afterglow
  18. GRB 080710: Lick IR detection
  19. GRB 0800707: optical observations
  20. GRB 080710: Rapid PROMPT Observations
  21. GRB 080710: Swift-XRT refined analysis
  22. GRB080710: Swift/UVOT observations
  23. GRB 080710: Enhanced Swift-XRT position
  24. GRB 080710: Faulkes Telescope North observations
  25. UVOT white band observations of GRB080710
  26. GRB 080710: REM afterglow confirmation & brightening
  27. GRB 080710: KAIT OA candidate
  28. GRB 080710: Swift XRT position
  29. GRB 080710: Swift detection of a burst
  30. GRB 080707: possible break in the X-rays
  31. New Swift-XRT GRB products available online.
  32. GRB 080707: GROND Confirmation of the Optical Afterglow
  33. UVOT observations of GRB080707
  34. GRB 080707: Swift XRT refined analysis
  35. GRB 080707: Enhanced Swift-XRT position
  36. GRB 080707: VLT redshift
  37. GRB 080707: GROND Detection of the Optical Afterglow Candidate
  38. GRB 080707: Swift detection of a burst
  39. Refined analysis of Swift Trigger 316063, is IGR J08408-4503
  40. Trigger 316063: Swift detection of a transient
  41. GRB 080702B: GROND Upper Limits
  42. GRB 080703: Swift-XRT refined analysis
  43. GRB 080703: UVOT Follow-Up Observation
  44. GRB 080703: VLT observations of the afterglow
  45. GRB 080703: Enhanced Swift-XRT position
  46. GRB 080703: Swift detection of a burst with optical afterglow
  47. GRB 080703A: ROTSE-III Detection of Optical Counterpart
  48. No radio detection from the short GRB 080702A
  49. Swift/UVOT observation of GRB080702A
  50. GRB 080702B: Swift XRT and UVOT observations
  51. GRB 080702A: MITSuME Akeno optical upper limits
  52. GRB 080701A: Early RAPTOR optical limits
  53. Swift Trigger 315630: Swift/UVOT Upper Limits
  54. GRB 080702A: Swift-XRT Team refined analysis
  55. GRB 080702B : Burst detected in BAT during Swift slew
  56. GRB 080702A: Enhanced Swift-XRT position
  57. Swift Trigger 315630: Probably not a GRB
  58. GRB 080702: Swift detection of a short burst
  59. GRB 080701: Swift-XRT refined analysis
  60. GRB 080701A, VATT optical upper limit
  61. GRB 080701A: Swift/UVOT Upper Limits
  62. GRB 080701A: Early Super-LOTIS Observations
  63. GRB 080701: Enhanced Swift-XRT position
  64. Trigger 315630: Swift detection of a possible burst
  65. GRB 080701: Swift-XRT Prompt Analysis
  66. GRB 080701: Swift detection of a burst
  67. GRB 080625: Swift/UVOT Follow-Up Observations
  68. GRB 080625:Swift-XRT detection of the afterglow
  69. GRB 080625: Swift/UVOT Detection of an Optical Afterglow
  70. GRB 080625: Observations at OSN
  71. GRB 080623: GROND upper limits
  72. GRB080623: Swift UVOT followup observations
  73. GRB 080623: Swift-XRT refined analysis
  74. GRB 080623: Enhanced Swift-XRT position
  75. GRB 080623: TAROT La Silla observatory optical observations
  76. GRB 080623: Swift/UVOT Non-Detection of an Optical Afterglow
  77. GRB 080623: Swift XRT prompt analysis
  78. GRB 080623: Swift detection of a burst
  79. Swift trigger 314975 is not a GRB
  80. GRB080607: optical observation
  81. GRB 080603b: optical observation
  82. GRB 070809: Putative host galaxy and redshift
  83. VLA upper limit on INTEGRAL burst GRB 080613A
  84. GRB 0800603A: optical observation
  85. GRB080613B: MITSuME upper limits
  86. GRB080613A: Optical upper limits with Okayama MITSuME telescope
  87. GRB 080603A: optical observations on June 04
  88. GRB 080613A: Swift-XRT detection of the afterglow
  89. GRB080613A: Swift/UVOT Upper Limits
  90. GRB 080613A: GROND Confirmation of the Afterglow Candidate
  91. GRB 080613B: GROND Upper Limits
  92. GRB 080613B - NOT optical and IR nondetections
  93. GRB080613B: Swift/UVOT Upper Limits
  94. GRB 080613B: Swift-XRT refined analysis
  95. GRB 080514B: Spectroscopic constraints and probable host galaxy
  96. GRB 080613B: Swift detection of a burst
  97. GRB 080603A: Late-time Keck imaging and spectroscopy
  98. GRB 080603b: optical observation
  99. Swift observations of BAT Slew Survey event (Trigger=010)
  100. GRB 080603A: final Swift-XRT observations.

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