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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"

28054 results found.

  1. GRB 150523A: Swift/UVOT Detection
  2. GRB 150513A: request for X-ray follow up
  3. GRB 150523A: LCOGT FTS afterglow confirmation
  4. GRB 150523A: LCOGT Cerro-Tololo optical afterglow candidate
  5. GRB 150523A Swift-XRT afterglow detection
  6. GRB 150523A: Fermi GBM detection
  7. Swift trigger 641332 is probably not an astrophysical source
  8. GRB 150518A: Continued RATIR optical observations
  9. GRB 150518A: MAXI-GSC further analysis
  10. GRB 150518A: Mondy optical observations
  11. GRB 150518A: MASTER-net before, early and after optical stereoscopic observations with possible MP discovery inside MAXI error box
  12. GRB 150518A: Swift-XRT follow-up observations
  13. GRB 150518A: SAO RAS optical observations
  14. GRB 150518A: RATIR optical observations
  15. GRB 150518A: GMG observation
  16. GRB 150518A: Xinglong2.16m optical afterglow detection
  17. Swift/UVOT observations of GRB150518A
  18. GRB 150518A: Swift-XRT afterglow detection
  19. GRB 150518A: MAXI/GSC detection
  20. GRB 150514A: GROND Bright Afterglow Confirmation
  21. GRB 150514A: Swift/UVOT Detection
  22. GRB 150514A: Swift-XRT afterglow detection
  23. GRB 150513A: Swift-BAT refined analysis
  24. GRB 150513A: Fermi GBM detection
  25. GRB 150512A: iPTF Optical Observations
  26. GRB 150510A: Fermi GBM detection
  27. GRB 150424A: 9.8 GHz VLA detection
  28. GRB 150423A: GMG observation limit
  29. Konus-Wind observation of GRB 150428A
  30. GRB 150423A: Chandra X-ray Observation
  31. Swift Trigger 639636: a possible GRB
  32. GRB 150430A: GROND Upper Limits
  33. GRB 150430A: Swift-BAT refined analysis
  34. GRB 150430A: Swift-XRT refined Analysis
  35. GRB 150430A: MAXI/GSC detection
  36. GRB 150430A: Swift/UVOT Upper Limits
  37. GRB 150430A: Swift detection of a burst
  38. GRB 150428B: IRSF NIR upper limits
  39. GRB 150428B: Swift/UVOT Upper Limits
  40. GRB 150428C: Swift-XRT observations
  41. GRB 150428A: Swift/UVOT Upper Limits
  42. GRB 150413A: CrAO optical observations
  43. GRB 150426A: Fermi GBM detection
  44. GRB 150428B: Swift-XRT refined Analysis
  45. GRB 150428A: Swift-XRT refined Analysis
  46. GRB 150428B: Swift-BAT refined analysis
  47. GRB 150428A: Swift-BAT refined analysis
  48. GRB 150428B: Enhanced Swift-XRT position
  49. GRB 150428C/MAXI J0400+678: MAXI/GSC detection
  50. GRB 150428A: Danish1.56m optical observations
  51. GRB 150428A: RATIR optical observations
  52. GRB 150428A: P60 observations
  53. GRB 150428A: Enhanced Swift-XRT position
  54. GRB 150428A: GROND Dark Burst Host Candidate
  55. GRB 150428B: Swift detection of a burst
  56. GRB 150428A: Swift detection of a burst
  57. Trigger 639199: Swift detection of IGRJ16418-4532
  58. GRB 150424A: RATIR Observations
  59. GRB 150424A: Swift-BAT refined analysis
  60. GRB 150424A: Swift-XRT refined Analysis
  61. GRB 150424A: GROND detects strong fading
  62. GRB 150423A: Continued RATIR optical afterglow monitoring
  63. GRB 150424A: Swift/UVOT Observations
  64. GRB 150423A: TSHAO optical observations
  65. GRB 150424A: Enhanced Swift-XRT position
  66. GRB 150423A: WHT observations
  67. GRB 150424B: MAXI/GSC detection
  68. GRB 150424A: Keck detection of optical afterglow
  69. GRB 150424A: Swift detection of a short burst
  70. GRB 150423A: MITSuME Okayama upper limits
  71. GRB 150423A: UKIRT NIR observations
  72. GRB 150423A: Swift-BAT refined analysis
  73. GRB 150423A: Swift/UVOT Upper Limits
  74. GRB 150423A: VLT detection
  75. GRB 150423A: Swift-XRT refined Analysis
  76. GRB 150423A: RATIR optical afterglow monitoring
  77. GRB 150423A: Enhanced Swift-XRT position
  78. GRB 150422A: Fermi GBM detection
  79. GRB 150423A: Keck optical afterglow confirmation
  80. GRB 150423A: GROND afterglow candidate
  81. GRB 150413A: Konus-Wind and Swift/BAT joint spectral analysis
  82. GRB 150423A: GROND observation
  83. GRB 150423A: Swift detection of a short burst
  84. Konus-Wind observation of GRB 150418A
  85. GRB150418A: Swift/UVOT did not detect a new source
  86. Further Swift XRT observations of GRB 150418A
  87. Swift trigger 638589 is probably not an astrophysical source
  88. GRB 150413A: Swift-XRT observations
  89. GRB 150418A: Swift-XRT observations
  90. GRB 150413A: RTT150 optical observations
  91. GRB 150418A: MAXI/GSC detection
  92. GRB 150413A: ISON-Ussuriysk optical observations
  93. GRB 150416A: Fermi GBM detection
  94. GRB 150413A: MITSuME Akeno Optical observation
  95. GRB 150413A: SAO RAS observations
  96. LOAO B, R Observations of GRB150413A
  97. Swift Trigger 638217 is probably not an astrophysical source
  98. GRB 150416A: Fermi-LAT detection
  99. GRB 150413A: GMG observation
  100. GRB 150413A

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