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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"

27419 results found.

  1. GRB 150428B: Swift-XRT refined Analysis
  2. GRB 150428B: MASTER-net prompt optical observation
  3. Fermi GBM trigger 150424722 is not a GRB
  4. GRB 150428A: MASTER-net early optical observation
  5. GRB 150428A: Swift-XRT refined Analysis
  6. GRB 150428B: Swift-BAT refined analysis
  7. GRB 150428A: Swift-BAT refined analysis
  8. GRB 150428A: RATIR optical observations
  9. GRB 150428A: P60 observations
  10. GRB 150428A: GROND Dark Burst Host Candidate
  11. GRB 150428B: Swift detection of a burst
  12. GRB 150428A: Swift detection of a burst
  13. Trigger 639199: Swift detection of IGRJ16418-4532
  14. GRB 150424A: RATIR Observations
  15. GRB 150424A: Swift-BAT refined analysis
  16. GRB 150424A: Swift-XRT refined Analysis
  17. GRB 150424A: spectral lag, extended-time emission
  18. GRB 150424A: 10.4m GTC spectroscopy
  19. GRB 150424A: GROND detects strong fading
  20. GRB 150424A: NOT optical observations
  21. GRB 150423A: VLT/X-shooter spectroscopy and tentative redshift
  22. GRB 150423A: Continued RATIR optical afterglow monitoring
  23. GRB 150424B: Fermi GBM detection
  24. Konus-Wind observation of GRB 150424A
  25. GRB 150424A: Swift/UVOT Observations
  26. GRB 150424A: Keck detection of optical afterglow
  27. GRB 150424A: Swift detection of a short burst
  28. GRB 150423A: Swift-BAT refined analysis
  29. GRB 150423A: Swift/UVOT Upper Limits
  30. GRB 150423A: Swift-XRT refined Analysis
  31. GRB 150423A: RATIR optical afterglow monitoring
  32. GRB 150422A: Fermi GBM detection
  33. GRB 150423A: Keck optical afterglow confirmation
  34. GRB 150423A: GROND afterglow candidate
  35. GRB 150413A: Konus-Wind and Swift/BAT joint spectral analysis
  36. GRB 150423A: GROND observation
  37. GRB 150423A: Swift detection of a short burst
  38. GRB150418A: Swift/UVOT did not detect a new source
  39. Swift trigger 638589 is probably not an astrophysical source
  40. GRB 150413A: Swift-XRT observations
  41. GRB 150416A: Fermi GBM detection
  42. Confirmation that Swift trigger 638217 is not an astrophysical source
  43. LOAO B, R Observations of GRB150413A
  44. Swift Trigger 638217 is probably not an astrophysical source
  45. GRB 150416A: Fermi-LAT detection
  46. GRB 150413A: GMG observation
  47. GRB 150413A: Bassano Bresciano Observatory optical observations
  48. Konus-Wind observation of a bright burst from SGR 1935+2154
  49. GRB 150413A: Swift-BAT refined analysis
  50. GRB 150413A: P60 photometry
  51. GRB 150413A: Nanshan optical and radio follow-ups
  52. GRB 150413A: Khureltogot optical observations
  53. GRB 150413A: MASTER bright OT detection
  54. GRB 150413A: Swift detection of a burst
  55. Swift trigger 637807 is probably not an astrophysical source
  56. Swift detection of SAX J1808.4-3658
  57. Swift GRB150402A: further XRT observations
  58. GRB 150407A: Swift-XRT observations
  59. GRB 150407A: optical observations
  60. GRB 150407A: Swift detection of a possible burst
  61. GRB 150407A: Swift ToO observations
  62. GRB 150403A: MASTER-net optical observation
  63. Swift triggered on a source in Terzan 5 (trigger=637212)
  64. GRB 150404A: Fermi GBM detection
  65. Konus-Wind observation of GRB 150403A
  66. Fermi trigger 449861706: MASTER-SAAO possible candidate to OT of Short GRB
  67. GRB 150403A: Swift-BAT refined analysis
  68. GRB 150403A: Fermi GBM Detection
  69. GRB 150403A: Swift/UVOT Detection
  70. GRB 150323C: Khureltogot optical observations
  71. GRB 150403A: Swift-XRT refined Analysis
  72. GRB 150403A: Fermi-LAT detection
  73. GRB 150403A: Swift detection of a burst with an optical counterpart
  74. GRB 150402A: results of Swift observations
  75. GRB 150402A: RATIR Optical Observations
  76. GRB 150402A: Swift ToO observations
  77. GRB 150402A detected in ground analysis of Swift-BAT data
  78. IPN Triangulation of GRB 150330A (long/very intense)
  79. GRB 150330A: Fermi GBM detection
  80. GRB 150323B: Swift-XRT afterglow detection
  81. GRB 141212A: GMG observation limit
  82. GRB 141220A: GMG observation limit
  83. GRB 141225A: GMG observation limit
  84. GRB 150120B: GMG observation
  85. Konus-Wind observation of GRB 150323B
  86. Konus-Wind observation of GRB 150323A
  87. GRB 150323B : Xinglong TNT upper limit
  88. GRB 150323C, Swift-BAT refined analysis
  89. GRB 150323C: Swift/UVOT Upper Limits
  90. GRB 150323B: Swift-XRT observations
  91. GRB 150323C: RATIR Optical Afterglow Observations
  92. GRB 150323C : Xinglong TNT optical observation
  93. GRB 150323C: Swift-XRT refined Analysis
  94. GRB 150323A, Swift-BAT refined analysis
  95. GRB150323C: Fermi GBM detection
  96. GRB 150323B: Fermi GBM observation
  97. GRB 150323C: MASTER-net optical observation
  98. GRB 150323C: Swift detection of a burst
  99. GRB 150323B: Swift ToO observations
  100. GRB 150323B detected in ground analysis of Swift-BAT data

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