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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"

7388 results found.

  1. GRB 090305: Swift detection of a short burst
  2. GRB 090205: Swift/UVOT Upper Limits
  3. GRB 090205: VLT candidate afterglow
  4. GRB 090205: Swift detection of a burst
  5. GRB090201: Swift UVOT upper limits
  6. GRB 090201: VLT NIR observations
  7. GRB 090201: VLT afterglow candidate
  8. GRB 090118: no afterglow candidate
  9. GRB 090123: Swift detection of a burst
  10. Trigger 340734: Swift detection of a possible short burst
  11. GRB 090118: Subaru NIR Observation
  12. GRB 090118: KPNO 4m 2nd Epoch Observations
  13. GRB 090118: KPNO 4m Detection of Candidate Afterglow
  14. GRB090118 Swift/UVOT upper limits
  15. GRB 090118: Possible burst detection from Swift-BAT slew data
  16. GRB090117: Swift-XRT detection of a possible candidate afterglow
  17. GRB 090113: LOAO Detection Limits in R, I, z, Y-band
  18. GRB 090113: Swift detection of a burst
  19. GRB 090111: Swift detection of a burst
  20. GRB 090107B: Swift/UVOT Observations
  21. Swift UVOT observations of GRB 090102
  22. GRB 090102: Swift detection of a burst with an optical counterpart
  23. GRB 081230: GROND confirmation of the afterglow
  24. GRB 081230: Swift detection of a burst
  25. GRB 081228: GROND confirmation of the optical/NIR afterglow
  26. GRB 081228: Swift detection of a burst
  27. GRB 081226B: Swift XRT and UVOT upper limits
  28. GRB 081226: GROND afterglow candidate
  29. GRB 081222: MITSuME optical observation
  30. GRB 081222:Optical afterglow observation
  31. GRB081222: REM candidate afterglow
  32. GRB 081222: Swift detection of a burst with a bright optical afterglow
  33. GRB 081221: Swift detection of a burst
  34. GRB 081118: Zadko observations
  35. GRB 081215A: Gamma Repeater?
  36. GRB 081211B(?): Possible burst detection from Swift-BAT slew data
  37. GRB 081211: Swift detection of a burst
  38. GRB 081210: Swift detection of a burst with optical afterglow
  39. GRB 081128: afterglow observations
  40. GRB 081128: Optical afterglow observations
  41. GRB 081204: GROND Observations
  42. GRB 081204: Swift XRT afterglow confirmation
  43. GRB 081204: Swift XRT afterglow candidate
  44. GRB 081203B: Swift-XRT candidate afterglow.
  45. GRB 081203A: Burst detection from Swift-BAT slew data
  46. GRB 081203: Swift detection of a burst with a bright optical counterpart
  47. Trigger 335971: Swift possible detection of a burst
  48. GRB 081128: Liverpool Telescope afterglow confirmation
  49. GRB 081128: Swift detection of a burst
  50. GRB 081127: Swift detection of a burst
  51. GRB 081126: Swift detection of a burst
  52. GRB081121: Swift/UVOT observations
  53. GRB 081121: ROTSE-III Detection of Optical Counterpart
  54. GRB 081118: VLT redshift
  55. GRB 081118: optical afterglow candidate
  56. GRB 081118: Swift detection of a burst
  57. GRB 081109: GROND Detection of the Optical/NIR Afterglow Candidate
  58. GRB 081109: Swift detection of a burst
  59. GRB 081104: GROND Detection of the Optical/NIR Afterglow Candidate?
  60. GRB 081102: Swift detection of a burst
  61. Swift-BAT triggered on a probable GRB 081101 (trigger=333320)
  62. GRB 081024B: new Swift-XRT observations
  63. GRB 081029: ROTSE-III Detection of Optical Counterpart
  64. GRB 081028: GROND Detection of the Optical/NIR Afterglow Candidate
  65. GRB 081028: Swift detection of a burst
  66. GRB 081025: TLS upper limits
  67. GRB 081025 BAT refined analysis
  68. GRB 081025: Burst detection from Swift-BAT slew data
  69. GRB 081024: Swift detection of a burst
  70. Swift detection of a possible burst (trigger 332287)
  71. GRB 081017: REM early observations
  72. GRB 081016B: Swift detection of a burst
  73. GRB 081016: Swift-XRT candidate afterglow detection
  74. GRB 081008: Galaxy associated with z=1.967 absorber
  75. GRB 081011: Swift detection of a burst
  76. GRB 081008: Swift detection of a burst with optical afterglow
  77. GRB 081007: Swift detection of a burst with optical afterglow
  78. Trigger 330353: Swift detection of a Galactic short soft burst
  79. GRB 080928: Swift detection of a burst with an optical counterpart
  80. Swift trigger 325707: Swift/UVOT Upper Limits
  81. GRB 080916C: IRSF/SIRUS NIR Observation
  82. GRB 080916C: GROND Confirmation of the Optical Afterglow
  83. GRB 080916C: GROND Confirmation of the Optical Afterglow
  84. GRB 080919: Swift detection of a short burst
  85. GRB 080916C: GROND Detection of the Optical Afterglow Candidate
  86. GRB 080916B: Swift UVOT Refined Analysis
  87. GRB 080916: REM candidate afterglow
  88. GRB 080916: Swift detection of a burst with optical afterglow
  89. GRB 080913: REM NIR early observations
  90. GRB 080913: GROND observation of a high-z optical/NIR afterglow candidate
  91. GRB 080913: Swift detection of a burst
  92. Swift-BAT/-XRT refined analysis on trigger 324362 (LS I +61 303)
  93. Swift trigger 324362 (LS I +61 303 ?): XRT
  94. GRB 080905A: MITSuME Akeno optical upper limits
  95. GRB 080905B: VLT redshift
  96. GRB 080906: Swift detection of a burst with optical afterglow
  97. GRB 080905B: Swift detection of a burst with possible optical counterpart
  98. GRB 080905: Swift detection of a probably-short burst
  99. GRB 080903: optical observations
  100. GRB 080903: Liverpool Telescope observations

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