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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"

27015 results found.

  1. GRB 120402A: optical upper limit
  2. GRB 120320A: early optical upper limit
  3. GRB 120403A, Swift-BAT refined analysis
  4. GRB 120402B: Fermi GBM detection
  5. GRB 120326A: Bassano Bresciano Observatory - correction for GCN Cir 13178
  6. GRB 120403A: Swift detection of a burst
  7. GRB 120402A: Swift detection of a possible burst or noise
  8. GRB 120326A: Cima Rest and Bassano Brescia
  9. GRB 120401A: Swift-XRT refined Analysis
  10. GRB 120401A: Swift-BAT refined analysis
  11. GRB 120401A: Swift detection of a burst
  12. GRB 120326A: Bassano Bresciano Observatory lightcurve analisis
  13. GRB 120326A : Suzaku WAM observation of the prompt emission
  14. GRB 120326A: CARMA 3mm detection
  15. Swift trigger 518853 is most likely GX 301-2
  16. GRB 120326A: Bassano Bresciano Observatory optical observations
  17. Swift trigger 518853: MASTER-ICATE possible OT
  18. The Swift-XRT source associated with trigger 518853 is a cosmic ray
  19. Trigger 518853: Swift detection of a probable Galactic transient
  20. GRB 120328B: Fermi-LAT Observations
  21. GRB 120327A: Zadko optical observations
  22. GRB 120328B: Fermi GBM detection
  23. GRB 120328A: Swift/UVOT Upper Limits
  24. GRB 120328A: Swift-XRT refined Analysis
  25. IPN Triangulation of GRB 120328B (long/intense)
  26. GRB 120328A: Swift-BAT refined analysis
  27. GRB 120328A: TAROT La Silla observatory optical observations
  28. Skynet/PROMPT observations of GRB120328A
  29. GRB 120328A: Swift detection of a burst
  30. GRB 120326A: Fermi GBM Observation
  31. GRB 120327A afterglow detection
  32. GRB 120326A: PAIRITEL NIR Observations
  33. GRB 120326A: Bassano Bresciano Observatory optical observations
  34. GRB 120327A: Swift-XRT refined Analysis
  35. GRB 120327A: Swift/UVOT further analysis
  36. GRB 120327A: Swift-BAT refined analysis
  37. GRB 120327A: X-shooter redshift
  38. GRB 120327A: Gemini-South redshift
  39. GRB 120327A: TAROT La Silla observatory optical decay
  40. GROND observations of GRB 120327A
  41. GRB 120327A: Liverpool Telescope Observations
  42. GRB 120327A: TAROT La Silla observatory optical detection
  43. GRB 120327A: Swift detection of a burst with an optical counterpart
  44. GRB 120326A: Swift-BAT refined analysis
  45. GRB 120326A: T17 optical observations
  46. GRB 120326A: Swift-XRT refined Analysis
  47. GRB 120326A: Swift/UVOT Detection
  48. GRB 120326A: Liverpool Telescope observations
  49. Skynet/Dolomiti Observations of GRB120326A
  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. IPN Triangulation of GRB 120323A (short/very intense)
  55. GRB 120324A: Swift-XRT refined Analysis
  56. Konus-Wind observation of GRB 120324A
  57. GRB 120323A: Fermi GBM detection
  58. GRB 120324A: GROND observations
  59. GRB 120324A: Swift-BAT refined analysis
  60. GRB 120324A: Swift/UVOT Upper Limits
  61. GRB 120324A: TAROT La Silla observatory optical observations
  62. GRB 120324A: Liverpool Telescope optical candidate
  63. GRB 120324A: UVOT Finding Chart Observation
  64. GRB 120324A: Swift detection of a burst
  65. GRB 120316A : Suzaku WAM observation of the prompt emission
  66. GRB 120320A: Zadko optical observations
  67. GRB 120316A: Fermi-GBM and Fermi-LAT Observations
  68. GRB 120320A: Swift/UVOT Upper Limits
  69. GRB 120320A , optical observations
  70. GRB 120320A: Swift-XRT refined Analysis
  71. GRB 120320A, Swift-BAT refined analysis
  72. Fermi GBM trigger 120319.237 is not a GRB
  73. Konus-Wind observation of GRB 120316A
  74. IPN Triangulation of GRB 120316A
  75. GRB 120320A: Swift detection of a burst
  76. GBM trigger 353549464 (GRB 120316A?) : High-energy photon emission in Fermi/LAT data
  77. Trigger 517876 is a Swift detection of GX 5-1
  78. Fermi GBM triggers 120309.265 and 120309.402 are not GRBs
  79. Fermi GBM triggers 120305.186, 120305.802 and 120306.823 are not GRBs
  80. GRB 120311A: Optical follow-up
  81. GRB 120311A: C88 optical limits
  82. GRB 120312A: Swift/UVOT Upper Limits
  83. GRB 120312A: Swift-XRT refined Analysis
  84. GRB 120312A: Swift-BAT refined analysis
  85. GRB 120311A: VLT/X-shooter observations
  86. GRB 120311B: C88 optical limits
  87. GRB 120312A: Swift detection of a burst
  88. GROND observations of GRB 120311A
  89. GRB 120311B: Swift/UVOT Upper Limits
  90. GRB 120311B: Faulkes Telescope North observations
  91. GRB 120311B: Swift-XRT refined Analysis
  92. GRB 120311A: Swift-XRT refined Analysis
  93. GRB 120311B: Swift-BAT refined analysis
  94. GRB 120311B: Swift-XRT observations
  95. GRB 120311A, Swift-BAT refined analysis
  96. GRB 120311B: Swift detection of a burst
  97. GRB 120311A: Swift/UVOT Upper Limits
  98. GRB 120311A: CAHA 1.23m I-band early observations
  99. GRB 120311A: Swift-XRT observations
  100. GRB 120311A: Liverpool Telescope optical candidate

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