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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"

26500 results found.

  1. GRB 101024A: Enhanced Swift-XRT position
  2. Swift/UVOT observations of GRB101023A
  3. GRB 101024A: Swift detection of a burst with an optical afterglow
  4. GGRB 101023A: GROND detection of the optical-NIR afterglow
  5. GRB 101023A: Swift-XRT Team Refined Analysis
  6. GRB 101023A: Gemini discovery of optical afterglow
  7. GRB 101023A: Enhanced Swift-XRT position
  8. GRB 101023A: REM NIR observations
  9. GRB 101023A: Swift detection of a burst
  10. GRB 101020A: MASTER prompt and afterglow limit
  11. GRB 101020A: BOOTES2 follow-up and limit
  12. GRB 101020A: MASTER polarization optical observations
  13. GRB 101020A, Swift-BAT refined analysis
  14. GRB 101017A: Swift XRT refined analysis
  15. GRB 101017A: Swift/UVOT Observations
  16. GRB 101008A: optical observations
  17. GRB101017A: MITSuME Okayama optical upper limits
  18. Konus-Wind observation of GRB 101017A
  19. GRB 101014A: Fermi LAT detection
  20. GRB 101017A: Enhanced Swift-XRT position
  21. GRB 101017A: Swift-BAT refined analysis
  22. GRB 101017A: Swift detection of a burst with optical counterpart
  23. GRB 101011A: Fermi GBM detection
  24. GRB 101014A: Fermi GBM detection
  25. GRB 100906A: D50 optical detection
  26. GRB 100902A: D50 optical limit
  27. GRB 101011A: Swift/UVOT observations
  28. GRB 101011A, GROND upper limits
  29. GRB 101011A: Zadko observatory - Gingin optical observations
  30. GRB 101011A: XRT Refined Analysis
  31. GRB 101011A: Swift/UVOT Observations of a Possible Optical Afterglow
  32. GRB 101011A: Enhanced Swift-XRT position
  33. GRB 101011A: Swift detection of a burst
  34. GRB 101008A: Fermi GBM observation
  35. GRB 101008A: MASTER prompt optical observations
  36. GRB101008A, GROND detection of a fading afterglow
  37. GRB 101008A: Swift-XRT refined analysis
  38. GRB 101008A: SAO RAS optical observations
  39. GRB 100915 optical upper limit
  40. GRB 101008: Swift/UVOT Upper Limits
  41. GRB 101008A: Enhanced Swift-XRT position
  42. GRB 101008A: Swift/XRT Detection of an Afterglow with no UVOT Counterpart
  43. Refined analysis shows Swift Trigger 435520 is not a GRB
  44. Swift Trigger 435520 is probably not a GRB
  45. GRB 100924A: Suzaku WAM observation of the prompt emission
  46. GRB 100924A: Fermi GBM observation
  47. GRB 100925A / MAXI J1659-152: WSRT Radio and Polarization Detection
  48. GRB100925A/MAXI J1659-152 MITSuME Ishigakijima and Okayama Optical Observation
  49. GRB 100925A / MAXI J1659-152: SARA-S Observations
  50. GRB 100925A/MAXI J1659-152: Submm observations from APEX
  51. GRB100925A/MAXI J1659-152: Galactic origin from SED analysis
  52. GRB 100925A/MAXI J1659-152 - NOT optical observations
  53. GRB 100925A / MAXI J1659-152: BOOTES-2/TELMA and IAC80 optical observations
  54. GRB 100925A: Nearby DSS Source - SN-GRB or new Galactic transient?
  55. GRB 100924A: GROND detection of an optical/NIR afterglow
  56. GRB 100925A: Swift detection of a burst
  57. GRB 100917A: TAROT La Silla observatory optical observations
  58. GRB 100915A: TAROT Calern observatory optical observations
  59. GRB100906A: Ashra-1 observation of early optical emission
  60. GRB 100916A: Fermi GBM detection
  61. GRB100915A: MITSuME Ishigakijima Optical upper limits
  62. GRB 100915B: GRT Optical Observation
  63. GRB 100915A: GRT Optical Observation
  64. GRB 100915B: Fermi GBM observation
  65. GRB 100915A: Swift/UVOT Upper Limits
  66. GRB 100915A: Swift-XRT refined analysis
  67. GRB 100915A: Enhanced Swift-XRT position
  68. GRB 100915B: a long GRB detected by INTEGRAL
  69. GRB 100915A: Swift detection of a likely burst
  70. GRB 100910A: Fermi GBM detection
  71. Swift BAT Trigger 433953 probably not a GRB
  72. GRB100909A: MITSuME Ishigakijima Optical upper limits
  73. GRB 100909A: Swift/UVOT observations
  74. GRB 100901A: errata of GRB name in GCN 11270
  75. GRB 100901A: optical observations in Mondy and R-light curve
  76. GRB 100909A: Swift-XRT refined analysis
  77. GRB 100906A: optical observations at Mt.Terskol
  78. GRB 100901A: optical observation in Maidanak, break confirmation
  79. GRB 100902A : Confirmation of afterglow and re-brightening with CFHT r’-band imaging
  80. GRB 100909A: Swift target of opportunity observation
  81. GRB 100909A: a long GRB detected by INTEGRAL
  82. GRB100906A: detection at 15GHz
  83. GRB100901A: IAO optical upper limits at 4 days after the burst
  84. GRB100906A: R band observations
  85. Konus-Wind observation of GRB 100906A
  86. GRB100906A: non-detection at 15GHz
  87. GRB100906A: Optical observations at IAO
  88. GRB 100906A: Fermi GBM observation
  89. GRB 100906A: Swift-XRT refined analysis
  90. GRB 100906A: Enhanced Swift-XRT position
  91. GRB 100906A: Swift/UVOT Observations
  92. GRB100906A: MITSuME Okayama Optical Observation
  93. GRB 100905A: Swift/UVOT Upper Limits
  94. GRB 100901A: TLS observations, SDSS calibration, decay slope
  95. GRB 100906A: Swift-BAT refined analysis
  96. GRB 100906A: Swift detection of a burst with an optical afterglow
  97. GRB 100829A: MASTER optical observations
  98. GRB100905A: Optical upper limits at IAO
  99. GRB100905A: MITSuME Okayama optical upper limits
  100. GRB 100905A: Swift-XRT refined analysis.

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