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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"

21459 results found.

  1. GRB050826: Swift-BAT detection of a long burst
  2. GRB050824: MASTER final analysis of the OT observations
  3. Possible GRB050825:MASTER optical observations
  4. Swift-BAT trigger 152038 is definitely not a GRB
  5. GRB050824: CORRECTION to UVOT observing times
  6. Swift-BAT trigger 152038 is probably not a GRB
  7. GRB050824: Swift/UVOT detection of fading afterglow
  8. GRB050824: decay of the XRT light curve and updated X-ray spectrum
  9. GRB050824, I-band imaging
  10. GRB 050822: refined XRT analysis
  11. GRB 050824: XRT refined analysis and possible afterglow detection
  12. GRB 050824: BAT refined analysis of a soft weak burst
  13. GRB050824: MASTER:OT decay
  14. GRB050824: MASTER observation OT
  15. GRB050805a: MASTER optical candidat
  16. GRB 050824: ROTSE-III Optical Limits
  17. GRB050824: Swift-BAT detection of a burst
  18. GRB050815: Maidanak optical observation
  19. GRB050822: Swift/UVOT upper limits
  20. GRB 050820A BAT observations of second, larger episode of emission
  21. GRB 050822: Swift-BAT refined analysis
  22. GRB 050820a - corrections to GCN 3846
  23. Swift/UVOT UV Photometry of GRB 050820B
  24. GRB 050822: ROTSE-III Prompt Optical Limits
  25. GRB 050822: Swift detection of a long burst
  26. Correction to Eiso calculation in GCN 3835 on GRB 050820A
  27. GRB050825a - very long GRB like GRB041219a? (Konus-Wind observation)
  28. GRB050820a BVRcIc field photometry
  29. GRB050820B XMM-Newton observation
  30. GRB 050820a: NIR Observations by WIRO
  31. GRB 050820B: Swift XRT position
  32. GRB050820B: Refined analysis of the Swift-BAT burst
  33. GRB050820B: BAT-Swift detection of a bright GRB
  34. Swift/UVOT photometry of GRB050820
  35. GRB050820: refined XRT analysis
  36. GRB 050820: Early RAPTOR detections
  37. GRB 050820 Swift-BAT refined analysis
  38. GRB050819: refined XRT analysis
  39. GRB 050820: Swift detection of a GRB
  40. GRB050820: Optical afterglow from P60
  41. GRB 050819 Swift-BAT refined analysis
  42. GRB050819: Swift XRT position
  43. GRB050819: Swift-BAT detection of a weak burst
  44. Swift-BAT trigger 150993 is not a GRB
  45. Swift Trigger 150823 is HETE J1900.1-2455
  46. GRB050817: Swift-BAT Detection of a burst
  47. GRB050815: Optical afterglow detection by Swift UVOT
  48. GRB050815: XRT refined analysis
  49. GRB 050813: Radio Observations
  50. GRB050815: Refined analysis of the Swift-BAT burst
  51. GRB 050815: ROTSE-III Optical Limits
  52. GRB050815: Swift XRT afterglow localization
  53. GRB050815: Swift-BAT detection of a burst
  54. GRB050814: Fading red source
  55. GRB 050813: Gemini Spectra Revisited
  56. GRB050814: P60 Optical Afterglow Candidate
  57. GRB 050814: XRT refined analysis
  58. GRB050814: SWIFT/UVOT observation
  59. GRB050814: Refined analysis of the Swift-BAT burst
  60. GRB 050813: Gemini spectroscopy and redshifts of galaxies B and C
  61. GRB 050814: Swift XRT Afterglow Localization
  62. GRB 050814: Swift detection of a burst
  63. GRB 050813: Magellan detection of a high redshift galaxy cluster
  64. GRB 050813: I-band observations
  65. GRB050813, SDSS pre-burst observations
  66. GRB 050813: KAIT optical limit
  67. GRB 050813: Swift-BAT refined analysis
  68. GRB 050813: Photometry of object in XRT error circle
  69. GRB050813: SWIFT/UVOT observation
  70. GRB 050813: Swift XRT afterglow localization
  71. GRB 050813: Possible Short Swift-BAT GRB
  72. GRB050813 (Swift 150139): P60 Observations
  73. Swift-BAT trigger 150131 is not a GRB
  74. GRB050803: CrAO optical observations, no OT candidate
  75. GRB 050803: PROMPT BVRcIc Observations
  76. GRB050805b: CrAO optical limit
  77. GRB050805a : Null detection report
  78. GRB050803, optical observations
  79. Swift-BAT trigger 149118 is very likely not a GRB
  80. Retraction of Swift Trigger 149131 (GRB 050805B)
  81. GRB 050805b: OHP optical limits
  82. GRB 050805b: TAROT optical limits
  83. GRB050805b: MASTER optical observations
  84. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  85. GRB050805a: MASTER optical candidat
  86. Swift-BAT trigger 149118 is probably not a GRB
  87. GRB 050803: RTT150 optical observations
  88. GRB050803: CrAO optical observations, possible OT candidate
  89. GRB050803: Optical/UV Upper Limits from Swift-UVOT
  90. GRB 050803: Keck Observations
  91. GRB 050803: Swift-BAT refined analysis
  92. GRB050803: MASTER further analys
  93. GRB 050803: Magellan Observations
  94. GRB 050803: early Swift XRT analysis results
  95. GRB 050803: TAROT optical limits
  96. GRB050803: MASTER optical observations
  97. GRB050803: Swift-BAT detection of a very long burst
  98. GCN GRB observation 050713A
  99. GRB 050802: Swift/UVOT optical and UV detections
  100. GRB050802 radio non-detection

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