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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"

43630 results found.

  1. Fermi trigger 368003226 : MASTER optical observations
  2. GRB 120819A: Swift/UVOT Upper Limits
  3. GRB 120817B: Deep limit on the optical afterglow from du Pont and Magellan observations
  4. GRB 120821A: Swift/XRT observations
  5. GRB 120821A: a long GRB detected by INTEGRAL
  6. GRB 120817B - PTF Observations
  7. GRB 120817A: RAPTOR Limits During Gamma-Ray Emitting Interval
  8. GRB 120811C: optical observations
  9. GRB 120817B: BAT location in ground analysis and refined analysis
  10. GRB 120819A: MASTER final limits
  11. GRB 120819A: Swift-BAT refined analysis
  12. GRB 120819A: GROND afterglow confirmation
  13. GRB 120819A: Swift-XRT refined Analysis
  14. GRB 120819A: Enhanced Swift-XRT position
  15. GRB 120819A: afterglow candidate from NOT
  16. GRB 120819A: MASTER optical observations
  17. GRB 120819A: Swift detection of a burst
  18. GRB 120817B: Swift-XRT observations
  19. GRB 120811C: optical observations
  20. GRB 120815A: MASTER-ICATE observations
  21. Konus-Wind observation of GRB 120816B
  22. IPN Triangulation of GRB 120816B (short/exceptionally intense)
  23. Konus-Wind observation of GRB 120817B
  24. GRB 120817A: Swift-XRT refined Analysis
  25. GRB 120817B: LCO Optical Observations
  26. GRB 120817B: Fermi GBM detection
  27. IPN Triangulation of GRB 120817B (short/very intense)
  28. GRB 120817A: Swift-BAT refined analysis
  29. GRB 120816A: optical upper limit
  30. GRB 120817A: Enhanced Swift-XRT position
  31. GRB 120817A: FTN and FTS observations
  32. GRB 120816A: Swift-XRT refined Analysis
  33. GRB 120817A: Swift-XRT observations
  34. GRB 120817A: Swift detection of a burst
  35. GRB 120816A: Enhanced Swift-XRT position
  36. GRB 120816A: Swift-BAT refined analysis
  37. GRB 120816A: BOOTES-2 observations
  38. GRB120816A: OPTIMA discovery of optical counterpart
  39. GRB 120816A: TAROT Calern observatory optical observations
  40. GRB 120816A: ROTSE-III Optical Limits
  41. GRB 120816A: Swift detection of a burst
  42. GRB 120815A: Swift-XRT refined Analysis
  43. GRB 120815A: Swift-BAT refined analysis
  44. GRB 120805A: Liverpool Telescope optical candidate detection
  45. GRB 120815A: Enhanced Swift-XRT position
  46. GRB 120815A: VLT/X-shooter redshift
  47. GRB 120815A: GROND afterglow candidate
  48. GRB 120815A: Swift-XRT observations
  49. GRB 120815A: TAROT La Silla observatory optical observations
  50. GRB 120815A: Swift detection of a burst
  51. GRB 120811B: Fermi GBM observation
  52. GRB 120804A: Possible temporal break in the X-ray light-curve
  53. GCN for GRB 120811C
  54. GRB 120811A: Swift/XRT-UVOT Obseravations
  55. GRB120804A: Chandra observations and afterglow detection
  56. GRB 120805A: optical afterglow confirmation from the NOT
  57. GRB 120805A: Enhanced Swift-XRT position
  58. GRB 120811C: EVLA Observations
  59. GRB 120811C: RTT150 optical observations
  60. GRB 120811C: MASTER-Tunka OT observations
  61. GRB 120811C: Swift-BAT refined analysis
  62. GRB 120811A: Swift-BAT refined analysis
  63. GRB 120811C: NOT redshift
  64. GRB 120811C: Bassano Bresciano Observatory optical observations
  65. GRB 120811C: Swift-XRT refined Analysis
  66. GRB 120811C: Swift/UVOT Detection
  67. GRB 120811C: Redshift from OSIRIS/GTC
  68. Improved IPN error box for short hard GRB 120811B
  69. GRB 120811C: RTT150 optical observations
  70. GRB 120811C: Enhanced Swift-XRT position
  71. GRB 120811C: TAROT Calern observatory optical observations
  72. GRB 120811C: MASTER-Amur observations of fading OT
  73. GRB 120811C: Swift detection of a burst with an optical counterpart
  74. Konus-Wind observation of GRB 120811B
  75. IPN Triangulation of short hard GRB 120811B
  76. Trigger 530588: Swift detection of XMM J174457-2850.3
  77. Swift Trigger 530581: GRB 120811A or a galactic transient
  78. GRB 120803A: optical upper limit
  79. GRB 120803A: Confirmation of the X-ray afterglow
  80. GRB 120804A: Konus-Wind and Swift/BAT joint spectral analysis
  81. GRB 120714B: GROND/FORS2 detection of a supernova
  82. Swift Trigger 530441 is a false trigger
  83. GRB 120804A: ATCA 34GHz upper limit
  84. GRB 120807A: Swift-XRT refined Analysis
  85. GRB 120802A: optical observations
  86. GRB 120807A: Fermi/LAT upper limit
  87. GRB 120807A: RAPTOR Limits During Gamma-Ray Emitting Interval
  88. GRB 120804A: Gemini-North detection of an optical afterglow and putative host galaxy
  89. GRB 120807A: TAROT La Silla observatory optical observations
  90. GRB 120807A: Swift-BAT refined analysis
  91. GRB 120807A: Enhanced Swift-XRT position
  92. GRB 120807A: Swift detection of a burst
  93. GRB 120804A: ATCA 34GHz upper limit
  94. Fermi/GBM detection of an SGR-like burst
  95. Swift-BAT trigger 530214 is noise
  96. GRB 120805A: Swift/UVOT Upper Limits
  97. Swift trigger 530214: uncertain if real or not
  98. Swift-BAT trigger 529813 is due to noise while entering the SAA
  99. GRB 120728A: Fermi GBM observation
  100. GRB 120805A: Swift-BAT refined analysis

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