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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"

37549 results found.

  1. GRB 150527A: LCOGT McDonald observations
  2. GRB 150527A: RATIR Afterglow Detection
  3. GRB 150523A: Suzaku WAM observation of the prompt emission
  4. GRB 150527A: Swift detection of a burst
  5. GRB 150523A: Swift ToO observations
  6. GRB 150523A: Swift/UVOT Detection
  7. GRB 150513A: request for X-ray follow up
  8. Konus-Wind observation of GRB 150523A
  9. GRB 150523A: LCOGT FTS afterglow confirmation
  10. GRB 150523A: LCOGT Cerro-Tololo optical afterglow candidate
  11. Confirmation that Swift Trigger 641332 is not astrophysical
  12. GRB 150523A Swift-XRT afterglow detection
  13. GRB 150523B: Swift ToO observations
  14. GRB 150523A: Fermi-LAT detection
  15. GRB 150523A: Fermi GBM detection
  16. GRB 150518A: Continued RATIR optical observations
  17. GRB 150518A: MAXI-GSC further analysis
  18. GRB 150518A: 6.0 GHz VLA detection
  19. GRB 150518A: MITSuME Akeno Optical observation
  20. GRB 150518A: Mondy optical observations
  21. GRB 150518A: AMI 15 GHz detection of possible radio counterpart
  22. GRB 150518A: MASTER-net before, early and after optical stereoscopic observations with possible MP discovery inside MAXI error box
  23. Konus-Wind observation of GRB 150518A
  24. GRB 150518A: Swift-XRT follow-up observations
  25. GRB 150518A : Xinglong TNT upper limit
  26. GRB 150518A: SAO RAS optical observations
  27. GRB 150518A: Correction
  28. GRB 150518A: VLT/X-shooter redshift of the likely host galaxy
  29. GRB 150518A: RATIR optical observations
  30. GRB 150518A: GMG observation
  31. GRB 150518A: Xinglong2.16m optical afterglow detection
  32. Swift/UVOT observations of GRB150518A
  33. GRB 150518A: Swift-XRT afterglow detection
  34. GRB 150518A: Tiled Swift observations
  35. GRB 150518A: MAXI/GSC detection
  36. GRB 150514A: Further Swift observations
  37. Konus-Wind observation of GRB 150514A
  38. GRB 150514A: VLT/X-shooter redshift
  39. GRB 150514A: GROND Bright Afterglow Confirmation
  40. GRB 150514A: Swift/UVOT Detection
  41. GRB 150514A: Fermi GBM Detection
  42. GRB 150514A: Swift-XRT afterglow detection
  43. GRB 150514A: Swift ToO observations
  44. GRB 150514A: Fermi-LAT detection
  45. GRB 150512A: CrAO optical observations
  46. GRB 150513A: Swift-BAT refined analysis
  47. GRB 150513A: Fermi GBM detection
  48. GRB 150513A: Fermi-LAT detection
  49. GRB 150512A: Fermi GBM detection
  50. GRB 150513A: Swift detection of a burst
  51. GRB 150512A: iPTF Optical Observations
  52. Konus-Wind observation of GRB 150510A
  53. GRB 150510A: Fermi GBM detection
  54. GRB 150510A: Fermi-LAT Refined Analysis
  55. GRB 150510A: Fermi-LAT detection
  56. GRB 150424A: 9.8 GHz VLA detection
  57. GRB 150423A: GMG observation limit
  58. Konus-Wind observation of GRB 150428A
  59. GRB 150423A: Chandra X-ray Observation
  60. Confirmation that Swift Trigger 639636 is not astrophysical
  61. Swift Trigger 639636: a possible GRB
  62. GRB 150423A: JCMT SCUBA-2 sub-mm observation
  63. GRB 150413A: AMI 15 GHz confirmation of radio counterpart
  64. GRB 150430A: GROND Upper Limits
  65. GRB 150430A: Swift-BAT refined analysis
  66. Konus-Wind observation of GRB 150430A
  67. GRB 150430A: Fermi GBM Detection
  68. GRB 150430A: Swift-XRT refined Analysis
  69. GRB 150430A: MAXI/GSC detection
  70. GRB 150430A: Swift/UVOT Upper Limits
  71. GRB 150430A: Swift detection of a burst
  72. GRB 150428B: IRSF NIR upper limits
  73. GRB 150428B: Swift/UVOT Upper Limits
  74. GRB 150428C: Swift-XRT observations
  75. GRB 150428A: Swift/UVOT Upper Limits
  76. GRB 150413A: CrAO optical observations
  77. GRB 150426A: Fermi GBM detection
  78. GRB 150428C: MASTER-net automatic optical inspection
  79. GRB 150428B: Swift-XRT refined Analysis
  80. GRB 150428B: MASTER-net prompt optical observation
  81. Fermi GBM trigger 150424722 is not a GRB
  82. GRB 150428A: MASTER-net early optical observation
  83. GRB 150428A: Swift-XRT refined Analysis
  84. GRB 150428B: Swift-BAT refined analysis
  85. GRB 150428C: Tiled Swift observations
  86. GRB 150428A: Swift-BAT refined analysis
  87. GRB 150428B: Enhanced Swift-XRT position
  88. GRB 150428C/MAXI J0400+678: MAXI/GSC detection
  89. GRB 150428A: Danish1.56m optical observations
  90. GRB 150428A: RATIR optical observations
  91. GRB 150428A: P60 observations
  92. GRB 150428A: Enhanced Swift-XRT position
  93. GRB 150428A: GROND Dark Burst Host Candidate
  94. GRB 150428B: Swift detection of a burst
  95. GRB 150428A: Swift detection of a burst
  96. GRB 150423A: MITSuME Akeno Optical observation
  97. GRB 150424A: RATIR Observations
  98. GRB 150424A: Swift-BAT refined analysis
  99. GRB 150424A: Swift-XRT refined Analysis
  100. GRB 150424A: spectral lag, extended-time emission

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