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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"

28062 results found.

  1. GRB 110827A, Swift-BAT refined analysis
  2. GRB 110825A: optical afterglow candidate
  3. GRB 110825A: field inspection and possible host galaxy
  4. GRB110825A: Swift target of opportunity observation
  5. IPN triangulation of GRB110825A (very intense, long-duration)
  6. GRB 110820A, the review of the sky area in plate archives
  7. Swift-BAT Trigger 501485 is noise
  8. Swift-BAT refined analysis of SFXT IGR J08408-4503 (trigger 501368)
  9. IPN triangulation of GRB 110820B (very long duration, extremely intense)
  10. GRB 110820A: Swift/UVOT Upper Limits
  11. GRB 110820A: Swift-XRT refined Analysis
  12. GRB110820A: MITSuME Ishigakijima Optical Upper Limits
  13. GRB 110820A: Swift-BAT refined analysis
  14. GRB 110820A: Enhanced Swift-XRT position
  15. GRB 110820A: CrAO optical upper limit
  16. GRB 110820A: Swift detection of a burst
  17. GRB 110818A: Swift/UVOT Upper Limits
  18. GRB 110818A: Enhanced Swift-XRT position
  19. GRB 110818A: Optical afterglow and redshift from VLT/X-shooter
  20. GRB 110818A: Swift-XRT refined Analysis
  21. GRB 110815A: Swift-XRT and UVOT refined Analysis
  22. GRB 110818A, Swift-BAT refined analysis
  23. GRB 110815A : Suzaku WAM observation of the prompt emission
  24. GRB 110818A: Swift detection of a burst
  25. GRB 110801A: Konus-Wind and Swift/BAT joint spectral analysis
  26. GRB 110801A: optical observations at Mt. Terskol observatory
  27. GRB 110812A: SuperAGILE localization of a long GRB.
  28. RXTE Discovery of the Spin Period of Swift J1834.9-0846
  29. GRB 110808A: Swift/UVOT Detection
  30. GRB 110808A: Swift-BAT refined analysis
  31. GRB 110808A: Swift-XRT refined Analysis
  32. SGR J1834.9-0846: A Neutron Star in W41?
  33. Swift SGR 1834.9-0846: Swift-BAT refined analysis
  34. GRB 110808A: Enhanced Swift-XRT position
  35. GRB 110808A: Swift detection of a burst with optical counterpart
  36. Fermi GBM detection of a SGR-like burst
  37. GRB 110807A: SAO RAS observations
  38. GRB 110807A: Swift detection of a burst or a posible new SGR
  39. GRB 110726A: two epochs of SAO RAS optical observations
  40. IPN triangulation of GRB110802A (short/hard burst)
  41. GRB 110801A: optical observations in CrAO
  42. EVLA observation for Fermi burst GRB 110721A
  43. GRB 110731A : Suzaku WAM observation of the prompt emission
  44. GRB 110726A: Swift-XRT refined Analysis
  45. GRB 110801A: SAO RAS optical observations
  46. GRB110801A: MITSuME Ishigakijima Optical Observation at 1 day after the burst
  47. GRB 110801A: Swift-BAT refined analysis
  48. Swift/UVOT observations of GRB110801A
  49. GRB 110801A: Swift-XRT refined Analysis
  50. GRB110801A: MITSuME Ishigakijima Optical Observation
  51. GRB 110801A: Enhanced Swift-XRT position
  52. GRB 110801A: Swift detection of a burst with an optical counterpart
  53. GRB110731A: MITSuME Ishigakijima Optical Upper Limits
  54. GRB 110731A Gemini-N redshift
  55. GRB 110731A: Swift-XRT refined Analysis
  56. GRB110731A: Swift/UVOT Observations
  57. GRB 110731A: Fermi GBM observation
  58. GRB 110731A: NOT photometry
  59. GRB 110731A: Enhanced Swift-XRT position
  60. GRB 110731A: Swift-BAT refined analysis
  61. GRB 110731A: FTN+FTS afterglow observations
  62. GRB 110731A: Swift detection of a burst with an optical counterpart
  63. Sw J1644+57 (GRB 110328A): Continued VLBA Observations
  64. INTEGRAL Weak trigger #6331: GRT Optical Observation
  65. GRB 110721A: Swift observations of afterglow candidate
  66. AXP 4U 0142+61: Swift-BAT refined analysis
  67. GRB 110726A: optical upper limit in CrAO
  68. Swift detection of a SGR-like burst from the AXP 4U 0142+61
  69. GRB110726A: MITSuME Ishigakijima Optical Observation
  70. GRB 110726A: Further Swift/UVOT Observations
  71. GRB110726A: Gemini-N tentative redshift
  72. GRB 110726A: Swift-BAT refined analysis
  73. GRB 110726A: Enhanced Swift-XRT position
  74. GRB 110726A: Swift/UVOT Detection
  75. GRB 110726A: Liverpool Telescope observations
  76. GRB 110726: ROTSE-III Detection of Optical Counterpart
  77. GRB 110726A: Swift detection of a burst
  78. IPN triangulation of GRB 110721A
  79. GRB 110721A: Preliminary Swift/UVOT Upper Limits
  80. GRB 110721A: potential counterpart candidate
  81. GRB 110721A: Fermi-LAT detection
  82. GRB 110721A: Fermi GBM detection
  83. GRB 110715A : Suzaku WAM observation of the prompt emission
  84. GRB 110719A: GRT Optical Observation
  85. GRB 110719A: optical limit by "Pi of the Sky"
  86. GRB 110719A: z-band upper limit
  87. Swift/UVOT observations of GRB110719A
  88. GRB 110719A: Swift-XRT refined Analysis
  89. GRB 110719A: optical upper limit
  90. GRB 110719A: Enhanced Swift-XRT position
  91. GRB 110719A: Swift-BAT refined analysis
  92. GRB 110719A: Swift detection of a burst
  93. GRB 110709B : Suzaku WAM observation of the prompt emission
  94. Swift J1822.3-1606: Transient Magnetar or Be X-ray Binary?
  95. GRB110715A: GROND Detection of the Optical/NIR Afterglow
  96. GRB 110715A: APEX detection of the submm counterpart
  97. GRB 110715A: Swift-XRT refined Analysis
  98. GRB 110715A: Swift/UVOT Detection
  99. GRB 110715A: Enhanced Swift-XRT position
  100. GRB 110715A: Swift-BAT refined analysis

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