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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 090514: Fermi GBM detection
  2. GRB 090518: Swift/UVOT Upper Limits
  3. GRB 090516: Observations from Stardome Observatory
  4. GRB090518: GROND upper limits
  5. GRB 090518: P60 Observations
  6. GRB 090518, Swift-BAT refined analysis
  7. GRB 090518B: Fermi GBM detection
  8. GRB 090516, RIMOTS optical upper limits
  9. GRB090513: Fermi GBM detection
  10. GRB090518 : Optical upper limit by MOA-II telescope
  11. GRB 090518: Swift-XRT refined analysis
  12. GRB 090518: Enhanced Swift-XRT position
  13. GRB 090518: Swift detection of a burst
  14. GRB 090515: Swift/BAT spectral lag results
  15. GRB 090516: Swift-BAT refined analysis
  16. GRB 090516: VLT spectrum (correction & update)
  17. GRB 090516: GROND OBSERVATIONS
  18. GRB 090516: VLT redshift
  19. GRB 090516 - Zadko Telescope observations
  20. GRB 090516: NOT optical observations
  21. GRB 090516: Swift XRT refined analysis
  22. GRB 090516: Swift/UVOT Observations
  23. GRB 090516: Enhanced Swift-XRT position
  24. GRB 090516: Faulkes Telescope South optical afterglow
  25. GRB 090516: Swift detection of a burst
  26. GRB 090515: VLA observations
  27. GRB 090515: Lick Upper Limits
  28. GRB 090515: ROVOR Upper Limit
  29. GRB 090515: MMT/MMIRS NIR Upper Limit
  30. GRB 090515: Swift/UVOT Observations
  31. GRB 090515: Swift-XRT refined analysis
  32. GRB 090515: Enhanced Swift-XRT position
  33. GRB 090509: Fermi GBM observation
  34. GRB 090515: Swift-BAT refined spectral analysis
  35. GRB 090515: Swift-BAT refined analysis
  36. GRB 090509 - Zadko Telescope observations
  37. GRB 090515: Gemini-N upper limit
  38. GRB 090515: WIYN NIR Upper Limit
  39. GRB 090515: Super-LOTIS Upper Limits
  40. GRB 090515: PAIRITEL Upper Limits
  41. GRB 090515: KAIT optical upper limits
  42. GRB 090515: ROTSE-III Optical Limits
  43. GRB 090515: Swift detection of a short burst
  44. GRB 090510: Suzaku WAM observation of the prompt emission
  45. GRB 090510, Radio limits
  46. GRB090510: VLT/FORS2 spectroscopic redshift
  47. GRB 090510: GROND observations
  48. GRB 090510: Swift/UVOT host galaxy candidates
  49. GRB 090510: Fermi-LAT follow-up analysis
  50. GRB 090509, further Swift-BAT refined analysis
  51. Fermi Gamma-ray Burst Monitor trigger 263649437 is not a GRB
  52. GRB 090510B: Fermi GBM detection
  53. GRB 090502: Fermi GBM detection
  54. GRB 090510: correction to GCN 9344
  55. Konus-Wind observation of GRB 090510
  56. AGILE detection of GRB 090510
  57. GRB 090510: UVOT refined analysis
  58. GRB 090510: Swift XRT refined analysis
  59. GRB 090510: correction to coordinates in GCN 9338
  60. GRB 090510: Enhanced Swift-XRT position
  61. GRB 090510: NOT afterglow confirmation
  62. GRB 090510: Swift-BAT refined analysis
  63. GRB 090510: Fermi GBM detection
  64. GRB 090509: Swift-BAT refined analysis
  65. Fermi LAT detection of GRB 090510
  66. GRB 090509, SMARTS optical/IR afterglow observations
  67. GRB 090510: Swift/UVOT Detection of a Candidate Optical Afterglow
  68. GRB 090510: Swift detection of a short hard burst
  69. GRB 090408: optical upper limit
  70. GRB 090418A: optical observation
  71. GRB 090509: GROND further analysis and redshift limit
  72. GRB 090509: REM NIR afterglow
  73. GRB 090509: GROND afterglow candidate
  74. GRB 090509: Swift detection of a burst
  75. GRB 090323: optical observations
  76. GRB 090423: optical limit
  77. GRB 090423: 250 GHz upper limit for a z=8.2 GRB with MAMBO-2 at the IRAM 30m
  78. GRB 080913: 250 GHz upper limit for a z=6.7 GRB with MAMBO-2 at the IRAM 30m
  79. GRB 090424: optical observations
  80. GRB 090427: GROND observations
  81. GRB 090429A: ROVOR magnitude limit
  82. ICSP VLF observation of GRB090427 from two receivers
  83. ICSP VLF observation of GRB090424 from four receivers
  84. Refined analysis of ICSP VLF observation of SGR J1550-5418 bursts on 22nd January, 2009
  85. GRB 090428B: Suzaku WAM observation of the prompt emission
  86. GRB 090424, SMARTS optical/IR afterglow monitoring
  87. GRB 090426: optical observations
  88. GRB 090429D: Fermi GBM detection
  89. GRB 090429C: Fermi GBM detection
  90. GRB 090429B: Swift/UVOT Upper Limits
  91. GRB 090429A: Swift/UVOT Upper Limits
  92. GRB 090427: pseudo-z= 1.48 from prompt emission spectrum
  93. GRB 090429B: Gemini-N further nIR observations
  94. GRB 090424: YNAO-GMG observations
  95. GRB 090429A: Swift-XRT refined analysis
  96. GRB 090429A: GROND upper limits
  97. GRB 090427C: Fermi GBM detection
  98. GRB 090427B: Fermi GBM detection
  99. GRB 090426C: Fermi GBM detection
  100. GRB 090426B: Fermi GBM detection/observation

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