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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 120327A: MITSuME Ishigakijima Optical Observation
  2. GRB 120326A: MITSuME Ishigakijima Optical Observation
  3. GRB 120328A: Swift-BAT refined analysis
  4. GRB 120328A: Enhanced Swift-XRT position
  5. GRB 120327A: NOT optical observations
  6. GRB 120328A: TAROT La Silla observatory optical observations
  7. GRB 120326A: Xinglong TNT further optical observation��correction for GCN Cir 13149)
  8. GRB 120326A: Xinglong TNT further optical observation
  9. Skynet/PROMPT observations of GRB120328A
  10. GRB 120328A: Swift detection of a burst
  11. GRB 120327A: GTC redshift confirmation
  12. GRB 120326A: Fermi GBM Observation
  13. GRB 120327A afterglow detection
  14. GRB 120326A: PAIRITEL NIR Observations
  15. GRB 120326A: Bassano Bresciano Observatory optical observations
  16. GRB 120327A: Swift-XRT refined Analysis
  17. GRB 120327A: CQUEAN grizY Observation
  18. GRB 120326A: LOAO R-band Observations
  19. GRB 120327A: Swift/UVOT further analysis
  20. GRB 120327A: Swift-BAT refined analysis
  21. GRB 120326A : SMA submm observation
  22. GRB 120327A: Enhanced Swift-XRT position
  23. GRB 120327A: X-shooter redshift
  24. GRB 120327A: Gemini-South redshift
  25. GRB 120327A: TAROT La Silla observatory optical decay
  26. GRB120326A: TNT optical observation
  27. GRB 120327A: IAC80 I-band observations
  28. GROND observations of GRB 120327A
  29. GRB 120327A: REM NIR and optical observations
  30. Skynet/PROMPT observations of GRB120327A
  31. GRB 120326A: Maisoncelles Observatory optical observations
  32. GRB 120327A: Liverpool Telescope Observations
  33. GRB 120327A: TAROT La Silla observatory optical detection
  34. GRB 120327A: Swift detection of a burst with an optical counterpart
  35. GRB 120326A: optical observation of GMG
  36. GRB 120326A : LOT optical observation
  37. GRB 120326A: Swift-BAT refined analysis
  38. GRB 120326A: T17 optical observations
  39. GRB 120326A: GTC redshift
  40. GRB 120326A: CQUEAN grizY Observation
  41. GRB 120323A: MASTER follow up observations
  42. GRB 120326A: Swift-XRT refined Analysis
  43. GRB 120326A: Swift/UVOT Detection
  44. GRB 120326A: Optical observations at Crni Vrh
  45. GRB120326A: IAC80 observations
  46. GRB 120326A: Liverpool Telescope observations
  47. GRB 120326A: Enhanced Swift-XRT position
  48. Skynet/Dolomiti Observations of GRB120326A
  49. GRB 120326A: TAROT Calern observatory afterglow optical decay
  50. GRB 120326A: TAROT Calern observatory afterglow optical detection
  51. GRB 120326A: ROTSE-III Optical Limits
  52. GRB 120326A: Swift detection of a burst
  53. GRB 120323A: Fermi LAT observations
  54. Konus-Wind observation of GRB 120323A
  55. IPN Triangulation of GRB 120323A (short/very intense)
  56. GRB 120324A: Swift-XRT refined Analysis
  57. Konus-Wind observation of GRB 120324A
  58. GRB 120323A: Fermi GBM detection
  59. GRB 120324A: GROND observations
  60. GRB 120324A: CQUEAN rizY Observation
  61. GRB 120324A: Swift-BAT refined analysis
  62. GRB 120324A: Swift/UVOT Upper Limits
  63. GRB 120324A: TAROT La Silla observatory optical observations
  64. GRB 120324A: Enhanced Swift-XRT position
  65. GRB 120324A: Liverpool Telescope optical candidate
  66. GRB 120324A: UVOT Finding Chart Observation
  67. GRB 120324A: Swift detection of a burst
  68. Simultaneous optical images of Swift pointing are available by GRT
  69. GRB 120316A : Suzaku WAM observation of the prompt emission
  70. GRB 120320A: Zadko optical observations
  71. GRB 120320A, the review of the sky area in plate archives
  72. GRB 120316A: Fermi-GBM and Fermi-LAT Observations
  73. GRB 120229A: Magellan observations and limit on an optical afterglow
  74. GRB 120320A: Swift/UVOT Upper Limits
  75. GRB 120320A: MITSuME Okayama Optical upper limits
  76. GRB 120320A , optical observations
  77. GRB 120320A: BOOTES-4 optical upper limit
  78. GRB 120320A: Swift-XRT refined Analysis
  79. GRB 120320A, Swift-BAT refined analysis
  80. GRB 120320A: Gemini-N and UKIRT observations
  81. Fermi GBM trigger 120319.237 is not a GRB
  82. GRB 120320A: Enhanced Swift-XRT position
  83. Konus-Wind observation of GRB 120316A
  84. IPN Triangulation of GRB 120316A
  85. GRB 120320A: MASTER optical observations
  86. GRB 120320A: Swift detection of a burst
  87. GBM trigger 353549464 (GRB 120316A?) : High-energy photon emission in Fermi/LAT data
  88. GRB 111228A: possible detection of the SN with the TNG
  89. Trigger 517876 is a Swift detection of GX 5-1
  90. GRB 120302A: Swift XRT refined analysis
  91. GRB 120312A, the review of the sky area in plate archives
  92. GRB 120312A: CrAO optical upper limit
  93. GRB 120312A: Gemini and UKIRT imaging
  94. GRB 120311A, the review of the sky area in plate archives
  95. Fermi GBM triggers 120309.265 and 120309.402 are not GRBs
  96. Fermi GBM triggers 120305.186, 120305.802 and 120306.823 are not GRBs
  97. GRB 120311A: Optical follow-up
  98. GRB 120311B: Optical follow-up
  99. GRB 120311A: C88 optical limits
  100. GRB 120312A: Swift/UVOT Upper Limits

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