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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 140105A: Fermi GBM detection
  2. GRB 140104B: Fermi GBM observation
  3. Fermi410578384: iPTF optical afterglow candidates for a possible short GRB
  4. GRB 140102A: BOOTES-4 early optical observations
  5. GRB 140104B: Fermi-LAT detection of a burst
  6. GRB 131209A: Further Swift XRT observations
  7. GRB 140103A: Lulin Optical r-band Observations
  8. GRB 131231A : Lulin Optical Observations
  9. GRB 131231A: CARMA 3mm detection
  10. Swift-BAT trigger 582894 is HR 1099 (Flare star)
  11. GRB140104A : Xinglong TNT observation. A bright star is located nearby
  12. GRB 140102A, Optical Observations
  13. GRB 131231A, Optical Observations
  14. GRB 140103A: P60 Observations
  15. GRB 140102A: P60 observations
  16. GRB 131231A: Swift/UVOT Observations of the Optical Afterglow
  17. GRB 131231A: Fermi GBM correction to GCN 15644
  18. GRB 140103A: Swift/UVOT Upper Limits
  19. Konus-Wind observation of GRB 131231A
  20. GRB 140102A: Fermi/GBM Observation
  21. GRB 131229A: Suzaku WAM observation of the prompt emission
  22. Konus-Wind observation of GRB 140102A
  23. GRB 140103A: Swift-XRT refined analysis
  24. GRB 140102A: GROND observations
  25. GRB 140103A, Swift-BAT refined analysis
  26. GRB 140102A: MAXI/GSC detection
  27. GRB 140102A, Swift-BAT refined analysis
  28. GRB 140102A: Swift-XRT refined Analysis
  29. GRB 140103A: MASTER-Net optical observations
  30. GRB 140102A: Fermi-LAT detection of a burst
  31. GRB 140102A: I-band observations from IAC80 and 1.23m CAHA telescopes
  32. GRB 140102A: Enhanced Swift-XRT position
  33. GRB 140103A: Swift detection of a burst
  34. GRB 140102A: Early optical observations from Nanshan
  35. GRB 131224B detected in ground analysis of Swift-BAT data
  36. GRB 140102A: Swift detection of a burst with optical counterpart
  37. GRB 131231A: Gemini-South Redshift
  38. GRB 131229A: Fermi GBM detection
  39. GRB 131231A: P60 observations
  40. GRB 131227A: KAIT light curve analysis
  41. GRB 131231A: Swift-XRT observations
  42. GRB 131231A : xinglong TNT optical observation
  43. GRB 131231A: MDM afterglow observation
  44. GRB 131231A: VLT/X-shooter redshift
  45. GRB 131231A: Fermi GBM detection
  46. GRB 131231A: iPTF optical afterglow candidate coincident with Nanshan detection
  47. GRB 131231A: afterglow confirmation from the NOT
  48. GRB 131231A: Nanshan afterglow candidate
  49. GRB 131231A: Fermi-LAT detection of a burst
  50. Konus-Wind observation of GRB 131229A
  51. GRB 131229A: CARMA 3mm observations
  52. GRB 131229A: Magellan upper limit
  53. GRB 131229A: GROND observations
  54. GRB 131229A: Swift-BAT refined analysis
  55. GRB 131229A: Swift-XRT refined Analysis
  56. GRB 131229A: Swift/UVOT Upper Limits
  57. GRB 131227A: GROND Upper Limits
  58. GRB 131229A: Enhanced Swift-XRT position
  59. GRB 131229A: Deep Gemini-South Imaging
  60. GRB 131229A: KAIT Optical Upper Limit
  61. GRB 131229A: P60 nondetection
  62. GRB 131229A: Swift detection of a burst
  63. GRB 131224A: 5.8 GHz VLA observations
  64. GRB 131227A: P60 Limits
  65. GRB 131227A: Gemini-North Redshift
  66. GRB 131227A: Swift-XRT refined Analysis
  67. GRB 131227A: Xinglong optical observations
  68. GRB 131227A: Swift/UVOT Upper Limits
  69. GRB 131227A: Swift-BAT refined analysis
  70. Konus-Wind observation of GRB 131226A
  71. GRB 131227A: Enhanced Swift-XRT position
  72. GRB 131227A: OT candidate from KAIT Optical observations
  73. GRB 131227A: Swift detection of a burst
  74. GRB 131224A: Swift/UVOT Upper Limits
  75. GRB 131225A: MASTER-Net optical observations
  76. GRB 131226A, Swift-BAT refined analysis
  77. GRB 131226A: Swift detection of a burst
  78. GRB 131216A: Suzaku WAM observation of the prompt emission
  79. GRB 131224A: Swift-XRT observation
  80. GRB 131225A: MAXI/GSC detection
  81. GRB 131224A: MASTER-Net early optical observations
  82. GRB 131224A: A short GRB detected by INTEGRAL
  83. GRB 131218A: GROND Upper Limits
  84. GRB 131218A: Swift XRT and UVOT observations
  85. Fermi Gamma-ray Burst Monitor trigger 409187680/131219968 is not a GRB
  86. GRB 131218A: Zadko observatory - Gingin optical candidate
  87. GRB 131218A: TAROT La Silla observatory optical observations
  88. GRB 131218A: a long GRB detected with INTEGRAL
  89. IPN Triangulation of GRB 131216A
  90. GRB 131216A: Fermi GBM observation
  91. GRB 131216A: Fermi-LAT detection of a burst
  92. GRB 131215A: MAXI/GSC detection
  93. Trigger 581129: Swift-BAT triggered on noise
  94. GRB 131205A: GROND confirmation of afterglow
  95. INTEGRAL Weak trigger #6403: AROMA-N Optical Observation
  96. GRB 131209A: Swift XRT and UVOT observations
  97. GRB 131209A: Fermi GBM observation
  98. GRB 131209A Tiled Swift observations
  99. Konus-Wind observation of GRB 131209A
  100. IPN Triangulation of GRB 131209A

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