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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"
  1. GRB101017A: MITSuME Okayama optical upper limits
  2. Konus-Wind observation of GRB 101017A
  3. GRB 101014A: Fermi LAT detection
  4. GRB 101017A: Enhanced Swift-XRT position
  5. GRB 101017A: Swift-BAT refined analysis
  6. GRB 101017A: ROTSE-III Optical Limits
  7. GRB 101017A: Swift detection of a burst with optical counterpart
  8. GRB 101011A: Fermi GBM detection
  9. GRB 101011A: BOOTES-3 Upper Limit
  10. Konus-Wind observation of GRB 101014A
  11. GRB 101014A: Fermi GBM detection
  12. GRB 100906A: D50 optical detection
  13. GRB 100902A: D50 optical limit
  14. GRB 101011A: Swift/UVOT observations
  15. GRB 101011A, GROND upper limits
  16. GRB 101011A: Zadko observatory - Gingin optical observations
  17. GRB 101011A: XRT Refined Analysis
  18. GRB 101011A: Swift/UVOT Observations of a Possible Optical Afterglow
  19. GRB 101011A: Enhanced Swift-XRT position
  20. GRB 101011A: Swift-BAT refined analysis
  21. GRB 101011A: Swift detection of a burst
  22. GRB 101008A: Fermi GBM observation
  23. GRB 101008A: MASTER prompt optical observations (correction to GCN#11328)
  24. GRB 101008A: MASTER prompt optical observations
  25. GRB 101008A: Swift-BAT refined analysis
  26. GRB101008A, GROND detection of a fading afterglow
  27. GRB 101008A: Swift-XRT refined analysis
  28. GRB 101008A: SAO RAS optical observations
  29. GRB 100915 optical upper limit
  30. GRB 101008: Swift/UVOT Upper Limits
  31. GRB 101008A: Enhanced Swift-XRT position
  32. GRB 101008A: 1.23m CAHA optical observations
  33. GRB 101008A: Swift/XRT Detection of an Afterglow with no UVOT Counterpart
  34. GRB 101008A: Swift detection of a burst
  35. GRB 100728B: X-shooter redshift
  36. Refined analysis shows Swift Trigger 435520 is not a GRB
  37. Swift Trigger 435520 is probably not a GRB
  38. GRB 100925A / MAXI J1659-152: MASTER optical observations
  39. GRB 100924A: Suzaku WAM observation of the prompt emission
  40. GRB 100928A, Swift-BAT refined analysis
  41. GRB 100924A: Fermi GBM observation
  42. GRB 100928A: Swift detection of a burst
  43. GRB 100925A / MAXI J1659-152: WSRT Radio and Polarization Detection
  44. GRB 100925A / MAXI J1659-152: Optical observation with the Kottamia 188cm telescope
  45. GRB100925A/MAXI J1659-152: X-shooter identification as an X-ray binary
  46. GRB100925A/MAXI J1659-152 MITSuME Ishigakijima and Okayama Optical Observation
  47. GRB 100925A / MAXI J1659-152: SARA-S Observations
  48. GRB 100925A/MAXI J1659-152: Submm observations from APEX
  49. GRB100925A/MAXI J1659-152: Galactic origin from SED analysis
  50. GRB 100925A/MAXI J1659-152 - NOT optical observations
  51. GRB 100925A / MAXI J1659-152: BOOTES-2/TELMA and IAC80 optical observations
  52. MAXI J1659-152: Swift-BAT refined analysis (triggers 434928 and 434931)
  53. GRB 100925A: Nearby DSS Source - SN-GRB or new Galactic transient?
  54. GRB100925A UVOT afterglow
  55. GRB 100924A: GROND detection of an optical/NIR afterglow
  56. GRB 100925A: Swift detection of a burst
  57. GRB 100924A: Swift-BAT refined analysis
  58. GRB 100924A: Swift detection of a burst
  59. GRB 100917A: TAROT La Silla observatory optical observations
  60. GRB 100915A: TAROT Calern observatory optical observations
  61. GRB100906A: Ashra-1 observation of early optical emission
  62. GRB 100916A: Fermi GBM detection
  63. GRB 100917A: Swift-BAT refined analysis
  64. GRB 100917A: Swift detection of a burst
  65. GRB100915A: MITSuME Ishigakijima Optical upper limits
  66. GRB 100915B: GRT Optical Observation
  67. GRB 100915A: GRT Optical Observation
  68. GRB 100915B: Fermi GBM observation
  69. GRB 100915A: Correction to Swift-BAT refined analysis
  70. GRB 100915A: Swift/UVOT Upper Limits
  71. GRB 100915A: Swift-BAT refined analysis
  72. GRB 100915A: Swift-XRT refined analysis
  73. GRB 100915A: Enhanced Swift-XRT position
  74. GRB 100915B: a long GRB detected by INTEGRAL
  75. GRB 100915A: Swift detection of a likely burst
  76. GRB 100910A: Fermi GBM detection
  77. Swift-BAT trigger 433953 is not a burst
  78. Swift BAT Trigger 433953 probably not a GRB
  79. GRB100909A: MITSuME Ishigakijima Optical upper limits
  80. GRB 100909A: Swift/UVOT observations
  81. GRB 100901A: errata of GRB name in GCN 11270
  82. GRB 100901A: optical observations in Mondy and R-light curve
  83. GRB100909A: NOT optical afterglow confirmation
  84. GRB 100909A: Swift-XRT refined analysis
  85. GRB 100906A: optical observations at Mt.Terskol
  86. GRB 100901A: optical observation in Maidanak, break confirmation
  87. GRB 100909A: Faulkes Telescope North afterglow candidate
  88. GRB 100909A: ROTSE-III Optical Limits
  89. GRB 100909A: Planned XMM-Newton observation
  90. GRB 100902A : Confirmation of afterglow and re-brightening with CFHT r’-band imaging
  91. GRB 100909A: Swift target of opportunity observation
  92. GRB 100909A: a long GRB detected by INTEGRAL
  93. GRB100906A: detection at 15GHz
  94. GRB100901A: IAO optical upper limits at 4 days after the burst
  95. EVLA detection of radio afterglow of GRB100901A
  96. GRB 100901A: Confirmation of WSRT Radio Detection
  97. GRB 100901A: CrAO optical observations
  98. GRB 100906A: RTT150 optical observations
  99. GRB 100906A: GRAS-007 optical observations
  100. GRB100906A: R band observations

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