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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"

35958 results found.

  1. GRB 100117A: candidate optical afterglow
  2. GRB 100119A: Swift detection of a burst
  3. Konus-Wind observation of GRB 100116A
  4. GRB 100117A: Gemini North spectroscopy
  5. GRB 100117A: Fermi GBM detection
  6. Swift/UVOT refined analysis of GRB100117A
  7. GRB 100117A: Optical object inside the revised XRT error circle
  8. GRB 100117A: Swift-XRT refined analysis
  9. GRB 100117A: Gemini-North upper limit
  10. GRB 100117A: Magellan IMACS imaging
  11. GRB 100117A: Gemini South Imaging and CFHT Pre-Explosion Images
  12. GRB 100117A: Swift-BAT refined analysis
  13. GRB 100117A: Swift detection of a short hard burst
  14. GRB 100115A: Gemini-N photometry
  15. GRB 100115A: Enhanced Swift-XRT position
  16. GRB 100116A: Fermi LAT detection
  17. GRB 100115A: SARA Astrometry
  18. GRB 100116A: Fermi GBM detection
  19. NOT observation of GRB100115A localization
  20. GRB 100115A: SARA Afterglow Candidate
  21. GRB 100115A: Swift/UVOT Upper Limits
  22. GRB 100115A: Swift-XRT candidate afterglow
  23. GRB 100115A detected in ground analysis of Swift-BAT data
  24. GRB 100111A: PAIRITEL NIR Upper Limits
  25. GRB 100111A: Swift UVOT Refined Analysis
  26. GRB 100111A: Swift-BAT refined analysis
  27. GRB 100111A: Enhanced Swift-XRT position
  28. GRB100111A: Swift-XRT refined analysis
  29. GRB 100111A: Fermi GBM observation
  30. GRB 100111A: NOT optical observations
  31. GRB 100111A: Swift detection of a burst with an optical afterglow
  32. GRB 100103A: GROND Upper Limits
  33. GRB 100103A: Swift-XRT team refined analysis
  34. GRB 100103A - UVOT-enhanced XRT position
  35. Konus-Wind observation of GRB 100103A
  36. GRB 100103A: Swift/UVOT Upper Limits
  37. GRB 100103A: Correction to Swift position error
  38. GRB 100103A: Swift/XRT position
  39. GRB 100103A: a long GRB detected with INTEGRAL
  40. Swift Trigger 381591 is probably not a burst
  41. GRB 091231: GROND NIR observations
  42. GRB 091230: Swift/UVOT Observations
  43. GRB 091230: Swift-XRT observation
  44. GRB 091230: GROND optical/NIR afterglow candidate
  45. GRB 091230: a long GRB detected by INTEGRAL
  46. Swift Trigger 381434 is not a GRB
  47. Trigger 381434: Swift detection of a possible burst
  48. GRB 091221 : IRSF NIR upper limit
  49. GRB 091221: Skynet/PROMPT Detections
  50. GRB 091221: Fermi GBM Observation
  51. GRB 091117: Swift-XRT late time observations
  52. GRB 091221 Swift-BAT refined analysis
  53. GRB 091221: Swift/UVOT refined analysis
  54. GRB 091221: Swift-XRT refined analysis
  55. GRB 091221: Enhanced Swift-XRT position
  56. GRB 091221, GROND observations
  57. GRB 091221: UVOT Confirmation of an Optical Afterglow
  58. GRB 091221: ROTSE-III Detection of Optical Counterpart
  59. GRB 091221: Swift detection of a burst
  60. Swift trigger 379449 (possible GRB) is not a burst
  61. GRB 091215: Faulkes Telescope North observations
  62. Trigger 379449: Swift detection of a possible burst
  63. GRB 091208B: Xinglong TNT optical observation
  64. GRB 091208A: Suzaku WAM observation of the prompt emission
  65. GRB 091208A: GAO 150cm telescope Optical Observation
  66. Konus-Wind observation of GRB 091208A
  67. GRB 091208B: GAO 150cm telescope Optical Observation
  68. GRB 091208B: optical observations
  69. GRB 091208B: Keck HIRES redshift confirmation
  70. GRB 091208B: GROND observations
  71. GRB 091208A: Swift-XRT observations
  72. GRB 091208B: Swift-XRT refined analysis
  73. GRB091208B: Swift/UVOT refined analysis
  74. GRB 091208B: Fermi GBM observation
  75. GRB 091208B, Swift-BAT refined analysis
  76. GRB 091208A Swift-BAT refined analysis
  77. GRB 091208B: Gemini-North redshift
  78. GRB 091208B: Faulkes Telescope North and South Optical Afterglow
  79. GRB 091208A, RIMOTS optical upper limits
  80. GRB 091208B: MITSuME Akeno Optical Observation
  81. GRB 091208B: Enhanced Swift-XRT position
  82. GRB 091208B: MITSuME Okayama Optical Observation
  83. GRB 091208B, RIMOTS optical upper limits
  84. GRB 091208B: Swift detection of a burst with an optical afterglow
  85. GRB 091208B: BOOTES-3 optical afterglow
  86. GRB 091208: ROTSE-III Optical Limits
  87. GRB 091208: Swift detection of a burst
  88. A small revision to the GRB-naming convention
  89. GRB 091123: Suzaku WAM observation of the prompt emission
  90. GRB 091127: Skynet/PROMPT Observations of Possible Host Galaxy
  91. GRB 091127: GAO 150cm telescope Optical Observation
  92. GRB 091202: GTC & CAHA optical/nIR afterglow candidate
  93. GRB 091109A: GROND confirmation of redshift z = 3.5
  94. GRB091127: Continuing Swift/UVOT Observations
  95. GRB 091127, SMARTS optical/IR afterglow observations
  96. GRB091202: Swift-XRT refined analysis
  97. GRB 091202: Swift/UVOT Upper Limits
  98. GRB 091202: Liverpool Telescope observations
  99. GRB 091202: Optical and NIR observations
  100. GRB 091202 - UVOT-enhanced XRT position

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