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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"

28081 results found.

  1. GRB 100728B: Continued KAIT observations
  2. GRB 100728B, Swift-BAT refined analysis
  3. GRB 100728B: Swift-XRT Refined Analysis
  4. GRB 100728A: GROND Detection of the NIR Afterglow Candidate
  5. GRB 100727A: Swift/UVOT Upper Limits
  6. GRB 100728A, Swift-BAT refined analysis
  7. GRB 100728B: Enhanced Swift-XRT position
  8. GRB 100728A: Swift/UVOT Upper Limits
  9. GRB 100728A: Swift-XRT refined analysis
  10. GRB 100728B: GROND Detection of the NIR Afterglow
  11. GRB 100728B: optical detection
  12. GRB 100728B: Swift detection of a burst with an optical counterpart
  13. GRB 100728A: Enhanced Swift-XRT position
  14. GRB 100728A: Swift detection of a burst
  15. GRB 100727A: Swift XRT refined analysis
  16. GRB 100727A, Swift-BAT refined analysis
  17. GRB 100727A: Enhanced Swift-XRT position
  18. GRB 100727A: Swift detection of a burst
  19. GRB100725B: MITSuME optical upper limits
  20. GRB 100724B: AGILE/GRID analysis
  21. GRB 100724B: Suzaku WAM observation of the prompt emission
  22. GRB 100724B: gamma-ray detection by AGILE
  23. GRB 100725B: Swift-BAT refined analysis
  24. GRB 100725B: refined XRT analysis
  25. GRB 100725A: GROND upper limits
  26. GRB 100725B: Swift/UVOT Upper Limits
  27. GRB 100725A: Swift/UVOT Upper Limits
  28. GRB 100725A: Swift-BAT refined analysis
  29. GRB 100725A: Swift XRT refined analysis
  30. GRB 100725B: Enhanced Swift-XRT position
  31. GRB 100725A: Enhanced Swift-XRT position
  32. GRB 100725B: Swift detection of a burst
  33. GRB 100725A: Swift detection of a burst
  34. GRB 100724B: Fermi GBM detection
  35. GRB 100724A: Swift XRT refined analysis
  36. GRB 100724A: Enhanced Swift-XRT position
  37. GRB 100724A: Swift/UVOT observations
  38. GRB 100724A: Swift-BAT refined analysis
  39. GRB 100724A: Swift detection of a burst
  40. GRB 100614A: 10.4-m GTC deep-optical limit
  41. GRB 100722A: Fermi GBM detection
  42. GRB 100718A: MASTER-Net optical prompt and alert observations
  43. GRB 100719A: Swift-BAT refined analysis
  44. GRB 100713A: optical observation in Maidanak
  45. GRB 100713A: Swift XRT refined analysis
  46. GRB 100713A: GROND upper limits
  47. GRB 100713A: TNG optical observations
  48. GRB100713A: Swift X-ray afterglow detection
  49. GRB 100713A: a long GRB detected by INTEGRAL
  50. GRB 100707A: Suzaku WAM observation of the prompt emission
  51. GRB 100707A: Fermi LAT detection
  52. GRB 100707A: Fermi GBM detection
  53. GRB 100628A: Chandra observations
  54. Tentative redshift of GRB100704A from Swift-XRT data
  55. GRB 100704A: Swift XRT refined analysis
  56. GRB 100704: Swift/UVOT Upper Limits
  57. GRB 100704A: Fermi GBM observation
  58. GRB 100704A: Swift-BAT refined analysis
  59. GRB 100704A: Enhanced Swift-XRT position
  60. GRB 100704A: Swift detection of a burst
  61. GRB 100615A: Additional Gemini/NIRI observations
  62. GRB 100526A: Gemini/NIRI afterglow confirmation and host galaxy
  63. GRB 100702A, Swift-BAT refined analysis
  64. GRB 100702A: Swift XRT refined analysis
  65. Swift/UVOT observations of GRB100702A
  66. GRB 100702A: Second epoch of Magellan near-IR observations and afterglow limits
  67. GRB 100701B: Fermi GBM detection
  68. GRB 100702A: Magellan near-IR observations
  69. GRB 100702A: VLT optical observations
  70. GRB 100702: ROTSE-III Optical Limits
  71. GRB 100702A: Swift detection of a short burst
  72. GRB 100615A: Chandra X-ray ToO Observation
  73. GRB 100213B: Detection of Fading Optical Afterglow
  74. GRB 100628A: GROND optical/NIR observations of the host candidate
  75. GRB 100628A: Gemini North Observations
  76. GRB100625A: GROND confirmation of constant source
  77. GRB 090709A: Host galaxy detection
  78. GRB 100628A: Swift/UVOT Upper Limits
  79. GRB100628A: RTT150 optical observations
  80. GRB 100628A: Swift-BAT refined analysis
  81. GRB 100628A: Swift detection of a short hard burst
  82. GRB 100614A: CrAO optical limit
  83. GRB 100625A: Swift/UVOT Upper Limits
  84. GRB 100625A: Swift-BAT refined analysis
  85. GRB 100625A: Swift-XRT Team refined analysis
  86. GRB 100625A: Enhanced Swift-XRT position
  87. GRB 100625A: Swift detection of a short hard burst
  88. GRB 100418A: late time optical observations
  89. GRB 100621A: IRSF/SIRIUS NIR Observation
  90. GRB 100621A: Swift/UVOT observations
  91. GRB 100621A: Swift XRT refined analysis
  92. GRB 100621A: Swift-BAT refined analysis
  93. GRB 100621A: GROND observation of bright NIR afterglow
  94. GRB 100621A: Enhanced Swift-XRT position
  95. GRB 100621A: ROTSE-III Optical Limits
  96. GRB 100621A: Swift detection of a burst
  97. GRB 100606A: Optical Limits
  98. GRB 100619A: Fermi GBM detection
  99. GRB 100619A: Swift/UVOT Upper Limits
  100. GRB 100619A: Swift-XRT refind analysis

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