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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"

28044 results found.

  1. GRB 101123A: MASTER prompt optical observations
  2. GRB 101123A: Fermi GBM detection
  3. GRB 101117B: GROND Upper limits
  4. GRB 101117B: Swift/UVOT Observations of the Optical Afterglow
  5. GRB 101112A: OSN and BTA observations
  6. XRF 101117A: Palomar Transient Factory Observations
  7. GRB 101117B: Swift-XRT refined analysis
  8. GRB101114A: Swift/UVOT Upper Limits
  9. GRB 101117B: Swift-BAT refined analysis
  10. GRB 101117B: Enhanced Swift-XRT position
  11. GRB 101117B: Swift detection of a burst
  12. GRB 101114A: GROND Upper limits
  13. Konus-Wind observation of GRB 101114A
  14. Fermi GBM detection of a burst from a galactic source
  15. GRB 101114A: Swift-XRT candidate afterglow detection and analysis
  16. GRB 101114A, Swift-BAT GRB detected by ground processing
  17. GRB 101112A: Fermi GBM detection
  18. GRB 101112A: optical observations
  19. Konus-Wind observation of GRB 101112A
  20. GRB 101112A - XRT source detection/analysis
  21. GRB101112A: Liverpool Telescope Afterglow Candidate
  22. GRB 101112A: a long GRB detected by INTEGRAL
  23. GRB 090113, the review of the sky area in plate archives
  24. GRB 101030A : MOA optical observation
  25. GRB 101030A: GROND optical/NIR afterglow candidate
  26. GRB 101030A : Swift XRT refined analysis
  27. GRB 101030A: Swift/UVOT Upper Limits
  28. GRB 101030A: Swift-BAT refined analysis
  29. GRB 101030A: Enhanced Swift-XRT position
  30. GRB 101030A: Swift detection of a burst
  31. GRB 090111, the review of the sky area in plate archives (1976-1996)
  32. GRB 101024A: GROND optical/NIR observations
  33. GRB 101024A: Swift XRT refined analysis
  34. GRB 101024A: Zadko observatory - Gingin. Optical observations
  35. GRB 101024A: Fermi GBM observation
  36. GRB101024A: Swift/UVOT
  37. GRB 101024A: Swift-BAT refined analysis
  38. GRB 101024A: Enhanced Swift-XRT position
  39. Swift/UVOT observations of GRB101023A
  40. GRB 101024A: Swift detection of a burst with an optical afterglow
  41. GGRB 101023A: GROND detection of the optical-NIR afterglow
  42. GRB 101023A: Swift-XRT Team Refined Analysis
  43. GRB 101023A: Swift-BAT refined analysis
  44. GRB 101023A: Gemini discovery of optical afterglow
  45. GRB 101023A: Enhanced Swift-XRT position
  46. GRB 101023A: REM NIR observations
  47. GRB 101023A: Swift detection of a burst
  48. GRB 101020A, Swift-BAT refined analysis
  49. GRB 101017A: Swift XRT refined analysis
  50. GRB 101017A: Swift/UVOT Observations
  51. GRB 101008A: optical observations
  52. GRB101017A: MITSuME Okayama optical upper limits
  53. GRB 101017A: Enhanced Swift-XRT position
  54. GRB 101017A: Swift-BAT refined analysis
  55. GRB 101017A: Swift detection of a burst with optical counterpart
  56. GRB 101014A: Fermi GBM detection
  57. GRB 100906A: D50 optical detection
  58. GRB 100902A: D50 optical limit
  59. GRB 101011A: Swift/UVOT observations
  60. GRB 101011A, GROND upper limits
  61. GRB 101011A: Zadko observatory - Gingin optical observations
  62. GRB 101011A: XRT Refined Analysis
  63. GRB 101011A: Swift/UVOT Observations of a Possible Optical Afterglow
  64. GRB 101011A: Enhanced Swift-XRT position
  65. GRB 101011A: Swift-BAT refined analysis
  66. GRB 101011A: Swift detection of a burst
  67. GRB 101008A: Swift-BAT refined analysis
  68. GRB101008A, GROND detection of a fading afterglow
  69. GRB 101008A: Swift-XRT refined analysis
  70. GRB 101008A: SAO RAS optical observations
  71. GRB 100915 optical upper limit
  72. GRB 101008: Swift/UVOT Upper Limits
  73. GRB 101008A: Enhanced Swift-XRT position
  74. GRB 101008A: Swift/XRT Detection of an Afterglow with no UVOT Counterpart
  75. GRB 101008A: Swift detection of a burst
  76. Refined analysis shows Swift Trigger 435520 is not a GRB
  77. Swift Trigger 435520 is probably not a GRB
  78. GRB 100925A / MAXI J1659-152: MASTER optical observations
  79. GRB 100924A: Suzaku WAM observation of the prompt emission
  80. GRB 100928A, Swift-BAT refined analysis
  81. GRB 100924A: Fermi GBM observation
  82. GRB 100928A: Swift detection of a burst
  83. GRB100925A/MAXI J1659-152 MITSuME Ishigakijima and Okayama Optical Observation
  84. GRB 100925A / MAXI J1659-152: SARA-S Observations
  85. GRB 100925A/MAXI J1659-152: Submm observations from APEX
  86. GRB100925A/MAXI J1659-152: Galactic origin from SED analysis
  87. GRB 100925A/MAXI J1659-152 - NOT optical observations
  88. GRB 100925A / MAXI J1659-152: BOOTES-2/TELMA and IAC80 optical observations
  89. GRB 100925A: Nearby DSS Source - SN-GRB or new Galactic transient?
  90. GRB100925A UVOT afterglow
  91. GRB 100924A: GROND detection of an optical/NIR afterglow
  92. GRB 100925A: Swift detection of a burst
  93. GRB 100924A: Swift-BAT refined analysis
  94. GRB 100917A: TAROT La Silla observatory optical observations
  95. GRB 100915A: TAROT Calern observatory optical observations
  96. GRB100906A: Ashra-1 observation of early optical emission
  97. GRB 100916A: Fermi GBM detection
  98. GRB 100917A: Swift-BAT refined analysis
  99. GRB 100917A: Swift detection of a burst
  100. GRB100915A: MITSuME Ishigakijima Optical upper limits

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