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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"

3137 results found.

  1. GRB 070318: Swift detection of a burst with an optical afterglow
  2. IPN localization of very bright long hard GRB 070207
  3. RHESSI Spectrum of GRB070125
  4. Konus-Wind observation of GRB 061222A
  5. GRB 061222b, SMARTS optical/IR afterglow observations
  6. GRB 061217: ROTSE-III Optical Limits
  7. GRB 061121: Second Epoch ATCA Radio Observations
  8. GRB 061126: Early Detection of the IR Afterglow
  9. GRB 061121: MDM Continued Monitoring
  10. GRB 060928: Confirmation of the X-ray afterglow detected by Swift
  11. GRB 061006: Swift-BAT refined analysis of the short-hard burst
  12. IGR J08408-4503 (= V* LM Vel): Swift detection of a transient
  13. GRB 060928: Swift observations
  14. GRB 060923A: Keck and Gemini Observations
  15. GRB 060923, Swift-BAT refined analysis
  16. GRB 060908: Swift/UVOT Observations
  17. GRB 060906: observations with FRAM
  18. GRB 060904B: RTT150 optical observations
  19. GRB060814: Break in the XRT light curve
  20. GRB 060805B: Swift/UVOT Upper Limits
  21. GRB060719: prompt NIR observations with REM
  22. GRB050326: Host Galaxy Candidates
  23. GRB050124: Possible Host Galaxy
  24. GRB050223: Host Galaxy
  25. GRB 060522: PROMPT Optical Limits
  26. GRB 060507: Swift-BAT Refined Analysis
  27. GRB 060502: Swift detection of a burst with an optical counterpart
  28. GRB060428B, optical observation
  29. GRB 060428A: Refined analysis of the Swift-BAT burst
  30. GRB 060421: TTT Observations
  31. GRB060413: Swift/UVOT upper limits
  32. GRB 060413: Swift detection of a burst
  33. SGR 1900+14: BAT observations
  34. HETE Trigger 4043: ROTSE-III Optical Limits
  35. H4043, an unusual high-energy transient observed by HETE
  36. GRB 060322: Confirmation of Swift XRT afterglow
  37. GRB 060322: Swift XRT afterglow candidate
  38. GRB 060319: Swift detection of a burst
  39. Bright short hard GRB 060303: IPN localization and Konus spectrum
  40. GRB 060218/SN 2006aj: RBO optical observations
  41. GRB 060211A: Partial refined analysis on the Swift-BAT burst
  42. GRB 050826: Optical Afterglow and Host Galaxy
  43. GRB 060211: Swift detection of a long burst
  44. GRB 060130: PROMPT Observations
  45. GRB 060124: Swift-BAT detection of a burst
  46. GRB 060116: IR Candidate Afterglow
  47. GRB 060115: OT photometry with MITSuME
  48. Swift Trigger 172767 is not a GRB
  49. GRB 051105b: ART optical limits
  50. SGR 1806-20: continued moderate activity seen with INTEGRAL
  51. GRB 051022 Chandra Observations scheduled
  52. GRB051021b: Magellan IR Imaging
  53. GRB051008: optical candidate
  54. GRB051008: optical observation
  55. GRB051008: Radio Observation
  56. GRB 051008: Swift XRT position
  57. GRB 051008: Swift UVOT Candidate
  58. Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
  59. GRB 051001: Swift Detection of a Burst
  60. GRB050922B: Swift UVOT early upper limits.
  61. GRB 050922B: optical limit
  62. GRB050922B: Swift-BAT detection of a weak long burst
  63. Swift-BAT trigger 155764 is not a GRB
  64. Swift-BAT trigger 155764 is probably not a GRB
  65. GRB 050915: Swift detection of a GRB
  66. GRB050908: VLT R-band decay index.
  67. GRB 050908: Swift detection of a burst
  68. GRB050904: Optical Observations
  69. GRB 050826: Optical Candidate
  70. GRB050824: MASTER:OT decay
  71. GRB 050820: Swift detection of a GRB
  72. GRB050814: P60 Optical Afterglow Candidate
  73. Retraction of Swift Trigger 149131 (GRB 050805B)
  74. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  75. GRB 050802 : Lulin Optical follow-up observation
  76. GCN 050801: early Swift XRT analysis results
  77. GRB 050730: Swift XRT afterglow observations
  78. GRB050721A: Swift-BAT detection of a weak burst
  79. GRB 050626: Swift XRT observations
  80. GRB 050701: Swift XRT afterglow position
  81. Swift trigger 143708 is really GRB 050701
  82. GRB050603: Fading Afterglow observed by Swift UVOT
  83. GRB050504: Ashra-P2/3 monitor and Ashra-AFT response
  84. GRB050502b: Early Observation
  85. GRB 050509a: Swift-BAT refined analysis
  86. GRB 050509A: Optical observations
  87. GRB 050509a: Swift XRT Position
  88. GRB 050502a: Swift XRT Upper Limit
  89. GRB 050502a: Optical Observations
  90. GRB 050504: Swift XRT position
  91. GRB050502A: Optical Observations
  92. GRB 050502: Confirmed variability of the afterglow candidate +
  93. GRB050502 - Correction on the Optical Candidate from the Liverpool
  94. GRB050502 - Optical Candidate from the Liverpool Telescope
  95. GRB 050502: ROTSE-III Detection of Possible Counterpart
  96. GRB 050422: Swift-BAT refined analysis
  97. Swift Detection of GRB050421
  98. GRB 050416: Radio observations
  99. GRB 050412: Swift XRT Position
  100. GRB 050408: Optical limit at 20 min after the burst

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