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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 120724A: FTN optical afterglow candidate
  2. GRB 120724A: Swift detection of a burst
  3. GRB 120709A: Swift re-observation of the field of the X-ray counterpart candidate.
  4. GRB 120722A: Swift/UVOT Upper Limits
  5. GRB 120722A: VLT/X-shooter redshift of the host galaxy
  6. GRB 120722A: GROND detection of the afterglow
  7. GRB 120722A: 1.5m OSN I-band observations
  8. GRB 120722A: Swift-XRT refined Analysis
  9. GRB 120722A: Swift-BAT refined analysis
  10. GRB 120722A: Enhanced Swift-XRT position
  11. GRB 120722A: Correction for GCN circ.13500
  12. GRB 120722A: Xinglong TNT optical afterglow candidate
  13. GRB 120722A: Swift detection of a burst
  14. GRB 120716A: Fermi GBM observation
  15. GRB 120716A: EVLA Detection
  16. GRB 120716A: Swift-XRT detection
  17. GRB 120716A: Swift/XRT position consistent with that of the optical counterpart
  18. GRB 120716A: Redshift confirmation from VLT/X-shooter
  19. VLT/FORS2 redshift of GRB120716A
  20. GRB 120716A: GROND confirmation of the optical/NIR afterglow
  21. GRB 120716A: Typo correction in GCN 13490
  22. GRB 120716A: Optical decay from NOT
  23. GRB 120716A: Candidate Optical Afterglow from PTF
  24. Konus-Wind observation of GRB 120716A
  25. IPN Triangulation of unusual GRB 120716A
  26. Fermi GBM trigger 120716.498 is not a GRB
  27. GRB 120711A: ATCA 34GHz final observations (upper limit)
  28. GRB 120714B: Swift/UVOT Detection
  29. GRB 120714B: Swift-XRT refined Analysis
  30. GRB120714A: Swift/UVOT upper limits
  31. GRB 120714B: Swift-BAT refined analysis
  32. Swift-BAT refined analysis of 1E 1841-045 (Trigger=526660)
  33. GRB 120714A: GROND upper limits
  34. GRB 120714B: GROND confirmation of fading afterglow
  35. GRB 120714B: Redshift from VLT/X-shooter
  36. GRB 120714A: Swift-XRT refined Analysis
  37. Trigger 526660: Swift detection of 1 E 1841-045 (aka Kes 73)
  38. GRB 120624B: VLA Observations
  39. GRB 120714B: Position Correction and Candidate Optical Afterglow
  40. GRB 120714A: Swift-BAT refined analysis
  41. GRB 120714B: Swift detection of a burst
  42. GRB 120714A: Enhanced Swift-XRT position
  43. GRB 120712A: Fermi GBM observation
  44. GRB 120711A: INTEGRAL/SPI observations
  45. GRB120714A: UVOT non-detection
  46. GRB 120714A: Swift-XRT observations
  47. GRB120711B: MITSuME Ishigakijima upper limits
  48. GRB 120714A: Swift detection of a burst
  49. GRB 120711A: ATCA 34GHz further observations (upper limit)
  50. IPN Triangulation of GRB 120709A
  51. GRB 120712A: Swift/UVOT Detection
  52. GRB 120712A: VLT/Xshooter redshift
  53. GRB 120712A: Swift-XRT refined Analysis
  54. GRB 120712A Gemini-S redshift
  55. GRB 120712A: GROND Detection of the Optical/NIR Afterglow Candidate and photo-z
  56. GRB 120712A: Enhanced Swift-XRT position
  57. GRB 120712A: Swift-BAT refined analysis
  58. GRB 120712A: Swift detection of a burst with optical afterglow
  59. GRB 120711B: Swift-XRT refined Analysis
  60. GRB 120711A: Fermi LAT Detection
  61. GRB 120711A: ATCA 34GHz upper limit
  62. GRB 120711B: Swift-BAT refined analysis
  63. GRB 120711B: Swift/UVOT Upper Limits
  64. GRB 120711A: Swift/UVOT Observations
  65. GRB 120709A: Swift/UVOT Observations
  66. Konus-Wind observation of GRB 120711A
  67. GRB 120711A: Fermi LAT detection
  68. GRB 120711A: MASTER early OT detection
  69. GRB 120711A: Swift-XRT observations
  70. GRB 120711A Gemini-S likely redshift
  71. Konus-Wind observation of GRB 120709A
  72. GRB 120711A: REM NIR early time detection
  73. GRB 120711A: GROND photometric redshift
  74. GRB 120711A: Fermi GBM observation
  75. GRB 120711A: MAXI/GSC detection
  76. GRB 120711A: a possible X-ray transient
  77. GRB 120711A: an bright long GRB detected with INTEGRAL
  78. Continued Skynet/PROMPT observations of GRB120711A
  79. GRB 120711A: ROTSE-III confirm of Optical Counterpart
  80. Swift detection of GRB 120711B or a new Galactic transient
  81. Skynet/PROMPT Observations of GRB120711A
  82. GRB 120709A: Fermi GBM detection
  83. GRB 120709A: Swift-XRT observations
  84. GRB 120709A: Matched filter analysis of Fermi-LAT data
  85. GRB 120709A: optical afterglow limits
  86. Konus-Wind observation of GRB 120707A
  87. IPN Triangulation of GRB 120707A
  88. GRB 120709A: Fermi-LAT Detection
  89. GRB 120707A: Fermi GBM Detection of a Bright Burst
  90. GRB 120624B: mm detection at PdBI
  91. GRB 120703A: SMARTS optical/IR observations
  92. GBM triggers 120705.153 & 120705.322 were not GRBs
  93. GRB 120703A: Swift/UVOT Detection
  94. GRB 120703A: Fermi GBM detection
  95. GRB 120703A: Swift-XRT refined Analysis
  96. GRB 120703A: Enhanced Swift-XRT position
  97. GRB 120703A: Swift-BAT refined analysis
  98. GRB 120624B Suzaku WAM observation of the prompt emission
  99. Konus-Wind observation of GRB 120703A
  100. GRB 120703A: NOT optical observation

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