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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 120326A : Suzaku WAM observation of the prompt emission
  2. GRB 120326A: CARMA 3mm detection
  3. GRB 120324A, the review of the sky area in plate archives
  4. Swift trigger 518853 is most likely GX 301-2
  5. GRB 120326A: Bassano Bresciano Observatory optical observations
  6. GRB 120328A: MITSuME Ishigakijima Optical Upper Limits
  7. GRB 120326A: MITSuME Ishigakijima Optical Observation at 2 days afterthe burst
  8. GRB 120327A: MITSuME Ishigakijima Optical Upper Limits at 1 day afterthe burst
  9. Swift trigger 518853: MASTER-ICATE possible OT
  10. The Swift-XRT source associated with trigger 518853 is a cosmic ray
  11. Trigger 518853: Swift detection of a probable Galactic transient
  12. GRB 120328B: Fermi-LAT Observations
  13. GRB 120327A: Zadko optical observations
  14. GRB 120328B: Fermi GBM detection
  15. long/intense GRB 120328B: MASTER follow up observations
  16. GRB 120328A: Swift/UVOT Upper Limits
  17. GRB 120326A: Bassano Bresciano Observatory further optical observations
  18. GRB 120328A: Swift-XRT refined Analysis
  19. Konus-Wind observation of GRB 120328B
  20. IPN Triangulation of GRB 120328B (long/intense)
  21. GRB 120327A: MITSuME Ishigakijima Optical Observation
  22. GRB 120326A: MITSuME Ishigakijima Optical Observation
  23. GRB 120328A: Swift-BAT refined analysis
  24. GRB 120328A: Enhanced Swift-XRT position
  25. GRB 120327A: NOT optical observations
  26. GRB 120328A: TAROT La Silla observatory optical observations
  27. GRB 120326A: Xinglong TNT further optical observation��correction for GCN Cir 13149)
  28. GRB 120326A: Xinglong TNT further optical observation
  29. Skynet/PROMPT observations of GRB120328A
  30. GRB 120328A: Swift detection of a burst
  31. GRB 120327A: GTC redshift confirmation
  32. GRB 120326A: Fermi GBM Observation
  33. GRB 120327A afterglow detection
  34. GRB 120326A: PAIRITEL NIR Observations
  35. GRB 120326A: Bassano Bresciano Observatory optical observations
  36. GRB 120327A: Swift-XRT refined Analysis
  37. GRB 120327A: CQUEAN grizY Observation
  38. GRB 120326A: LOAO R-band Observations
  39. GRB 120327A: Swift/UVOT further analysis
  40. GRB 120327A: Swift-BAT refined analysis
  41. GRB 120326A : SMA submm observation
  42. GRB 120327A: Enhanced Swift-XRT position
  43. GRB 120327A: X-shooter redshift
  44. GRB 120327A: Gemini-South redshift
  45. GRB 120327A: TAROT La Silla observatory optical decay
  46. GRB120326A: TNT optical observation
  47. GRB 120327A: IAC80 I-band observations
  48. GROND observations of GRB 120327A
  49. GRB 120327A: REM NIR and optical observations
  50. Skynet/PROMPT observations of GRB120327A
  51. GRB 120326A: Maisoncelles Observatory optical observations
  52. GRB 120327A: Liverpool Telescope Observations
  53. GRB 120327A: TAROT La Silla observatory optical detection
  54. GRB 120327A: Swift detection of a burst with an optical counterpart
  55. GRB 120326A: optical observation of GMG
  56. GRB 120326A : LOT optical observation
  57. GRB 120326A: Swift-BAT refined analysis
  58. GRB 120326A: T17 optical observations
  59. GRB 120326A: GTC redshift
  60. GRB 120326A: CQUEAN grizY Observation
  61. GRB 120323A: MASTER follow up observations
  62. GRB 120326A: Swift-XRT refined Analysis
  63. GRB 120326A: Swift/UVOT Detection
  64. GRB 120326A: Optical observations at Crni Vrh
  65. GRB120326A: IAC80 observations
  66. GRB 120326A: Liverpool Telescope observations
  67. GRB 120326A: Enhanced Swift-XRT position
  68. Skynet/Dolomiti Observations of GRB120326A
  69. GRB 120326A: TAROT Calern observatory afterglow optical decay
  70. GRB 120326A: TAROT Calern observatory afterglow optical detection
  71. GRB 120326A: ROTSE-III Optical Limits
  72. GRB 120326A: Swift detection of a burst
  73. GRB 120323A: Fermi LAT observations
  74. Konus-Wind observation of GRB 120323A
  75. IPN Triangulation of GRB 120323A (short/very intense)
  76. GRB 120324A: Swift-XRT refined Analysis
  77. Konus-Wind observation of GRB 120324A
  78. GRB 120323A: Fermi GBM detection
  79. GRB 120324A: GROND observations
  80. GRB 120324A: CQUEAN rizY Observation
  81. GRB 120324A: Swift-BAT refined analysis
  82. GRB 120324A: Swift/UVOT Upper Limits
  83. GRB 120324A: TAROT La Silla observatory optical observations
  84. GRB 120324A: Enhanced Swift-XRT position
  85. GRB 120324A: Liverpool Telescope optical candidate
  86. GRB 120324A: UVOT Finding Chart Observation
  87. GRB 120324A: Swift detection of a burst
  88. Simultaneous optical images of Swift pointing are available by GRT
  89. GRB 120316A : Suzaku WAM observation of the prompt emission
  90. GRB 120320A: Zadko optical observations
  91. GRB 120320A, the review of the sky area in plate archives
  92. GRB 120316A: Fermi-GBM and Fermi-LAT Observations
  93. GRB 120229A: Magellan observations and limit on an optical afterglow
  94. GRB 120320A: Swift/UVOT Upper Limits
  95. GRB 120320A: MITSuME Okayama Optical upper limits
  96. GRB 120320A , optical observations
  97. GRB 120320A: BOOTES-4 optical upper limit
  98. GRB 120320A: Swift-XRT refined Analysis
  99. GRB 120320A, Swift-BAT refined analysis
  100. GRB 120320A: Gemini-N and UKIRT observations

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