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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"

2850 results found.

  1. GRB 070611: Watcher Observations
  2. GRB 070612B: KAIT limits
  3. GRB 070610: OPTIMA-Burst detection of continued strong flaring activity
  4. GRB 070521: optical limit by Pi of the Sky
  5. GRB 070506, Swift-BAT Refined Analysis
  6. GRB 070506: Swift detection of a burst with optical afterglow
  7. GRB 070429: Swift detection of a burst
  8. GRB 070427: Swift detection of a burst
  9. GRB 070420 Swift-BAT Refined Analysis
  10. GRB070419A, optical observation
  11. GRB 070412: Optical observations at Crni Vrh
  12. GRB 070411: Tautenburg RRM Afterglow Confirmation
  13. GRB 070406: Xinglong TNT optical Upper Limit
  14. GRB 070318: Swift detection of a burst with an optical afterglow
  15. IPN localization of very bright long hard GRB 070207
  16. RHESSI Spectrum of GRB070125
  17. Konus-Wind observation of GRB 061222A
  18. GRB 061222b, SMARTS optical/IR afterglow observations
  19. GRB 061217: ROTSE-III Optical Limits
  20. GRB 061121: Second Epoch ATCA Radio Observations
  21. GRB 061126: Early Detection of the IR Afterglow
  22. GRB 061121: MDM Continued Monitoring
  23. GRB 060928: Confirmation of the X-ray afterglow detected by Swift
  24. GRB 061006: Swift-BAT refined analysis of the short-hard burst
  25. IGR J08408-4503 (= V* LM Vel): Swift detection of a transient
  26. GRB 060928: Swift observations
  27. GRB 060923A: Keck and Gemini Observations
  28. GRB 060923, Swift-BAT refined analysis
  29. GRB 060908: Swift/UVOT Observations
  30. GRB 060906: observations with FRAM
  31. GRB 060904B: RTT150 optical observations
  32. GRB060814: Break in the XRT light curve
  33. GRB 060805B: Swift/UVOT Upper Limits
  34. GRB060719: prompt NIR observations with REM
  35. GRB050326: Host Galaxy Candidates
  36. GRB050124: Possible Host Galaxy
  37. GRB050223: Host Galaxy
  38. GRB 060522: PROMPT Optical Limits
  39. GRB 060507: Swift-BAT Refined Analysis
  40. GRB 060502: Swift detection of a burst with an optical counterpart
  41. GRB060428B, optical observation
  42. GRB 060428A: Refined analysis of the Swift-BAT burst
  43. GRB 060421: TTT Observations
  44. GRB060413: Swift/UVOT upper limits
  45. GRB 060413: Swift detection of a burst
  46. SGR 1900+14: BAT observations
  47. HETE Trigger 4043: ROTSE-III Optical Limits
  48. H4043, an unusual high-energy transient observed by HETE
  49. GRB 060322: Confirmation of Swift XRT afterglow
  50. GRB 060322: Swift XRT afterglow candidate
  51. GRB 060319: Swift detection of a burst
  52. Bright short hard GRB 060303: IPN localization and Konus spectrum
  53. GRB 060218/SN 2006aj: RBO optical observations
  54. GRB 060211A: Partial refined analysis on the Swift-BAT burst
  55. GRB 050826: Optical Afterglow and Host Galaxy
  56. GRB 060211: Swift detection of a long burst
  57. GRB 060130: PROMPT Observations
  58. GRB 060124: Swift-BAT detection of a burst
  59. GRB 060116: IR Candidate Afterglow
  60. GRB 060115: OT photometry with MITSuME
  61. Swift Trigger 172767 is not a GRB
  62. GRB 051105b: ART optical limits
  63. SGR 1806-20: continued moderate activity seen with INTEGRAL
  64. GRB 051022 Chandra Observations scheduled
  65. GRB051021b: Magellan IR Imaging
  66. GRB051008: optical candidate
  67. GRB051008: optical observation
  68. GRB051008: Radio Observation
  69. GRB 051008: Swift XRT position
  70. GRB 051008: Swift UVOT Candidate
  71. Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
  72. GRB 051001: Swift Detection of a Burst
  73. GRB050922B: Swift UVOT early upper limits.
  74. GRB 050922B: optical limit
  75. GRB050922B: Swift-BAT detection of a weak long burst
  76. Swift-BAT trigger 155764 is not a GRB
  77. Swift-BAT trigger 155764 is probably not a GRB
  78. GRB 050915: Swift detection of a GRB
  79. GRB050908: VLT R-band decay index.
  80. GRB 050908: Swift detection of a burst
  81. GRB050904: Optical Observations
  82. GRB 050826: Optical Candidate
  83. GRB050824: MASTER:OT decay
  84. GRB 050820: Swift detection of a GRB
  85. GRB050814: P60 Optical Afterglow Candidate
  86. Retraction of Swift Trigger 149131 (GRB 050805B)
  87. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  88. GRB 050802 : Lulin Optical follow-up observation
  89. GCN 050801: early Swift XRT analysis results
  90. GRB 050730: Swift XRT afterglow observations
  91. GRB050721A: Swift-BAT detection of a weak burst
  92. GRB 050626: Swift XRT observations
  93. GRB 050701: Swift XRT afterglow position
  94. Swift trigger 143708 is really GRB 050701
  95. GRB050603: Fading Afterglow observed by Swift UVOT
  96. GRB050504: Ashra-P2/3 monitor and Ashra-AFT response
  97. GRB050502b: Early Observation
  98. GRB 050509a: Swift-BAT refined analysis
  99. GRB 050509A: Optical observations
  100. GRB 050509a: Swift XRT Position

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