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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"

21455 results found.

  1. GRB050824: CORRECTION to UVOT observing times
  2. Swift-BAT trigger 152038 is probably not a GRB
  3. GRB050824: Swift/UVOT detection of fading afterglow
  4. GRB050824: decay of the XRT light curve and updated X-ray spectrum
  5. GRB050824, I-band imaging
  6. GRB 050822: refined XRT analysis
  7. GRB 050824: XRT refined analysis and possible afterglow detection
  8. GRB 050824: BAT refined analysis of a soft weak burst
  9. GRB050824: MASTER:OT decay
  10. GRB050824: MASTER observation OT
  11. GRB050805a: MASTER optical candidat
  12. GRB 050824: ROTSE-III Optical Limits
  13. GRB050824: Swift-BAT detection of a burst
  14. GRB050815: Maidanak optical observation
  15. GRB050822: Swift/UVOT upper limits
  16. GRB 050820A BAT observations of second, larger episode of emission
  17. GRB 050822: Swift-BAT refined analysis
  18. GRB 050820a - corrections to GCN 3846
  19. Swift/UVOT UV Photometry of GRB 050820B
  20. GRB 050822: ROTSE-III Prompt Optical Limits
  21. GRB 050822: Swift detection of a long burst
  22. Correction to Eiso calculation in GCN 3835 on GRB 050820A
  23. GRB050825a - very long GRB like GRB041219a? (Konus-Wind observation)
  24. GRB050820a BVRcIc field photometry
  25. GRB050820B XMM-Newton observation
  26. GRB 050820a: NIR Observations by WIRO
  27. GRB 050820B: Swift XRT position
  28. GRB050820B: Refined analysis of the Swift-BAT burst
  29. GRB050820B: BAT-Swift detection of a bright GRB
  30. Swift/UVOT photometry of GRB050820
  31. GRB050820: refined XRT analysis
  32. GRB 050820: Early RAPTOR detections
  33. GRB 050820 Swift-BAT refined analysis
  34. GRB050819: refined XRT analysis
  35. GRB 050820: Swift detection of a GRB
  36. GRB050820: Optical afterglow from P60
  37. GRB 050819 Swift-BAT refined analysis
  38. GRB050819: Swift XRT position
  39. GRB050819: Swift-BAT detection of a weak burst
  40. Swift-BAT trigger 150993 is not a GRB
  41. Swift Trigger 150823 is HETE J1900.1-2455
  42. GRB050817: Swift-BAT Detection of a burst
  43. GRB050815: Optical afterglow detection by Swift UVOT
  44. GRB050815: XRT refined analysis
  45. GRB 050813: Radio Observations
  46. GRB050815: Refined analysis of the Swift-BAT burst
  47. GRB 050815: ROTSE-III Optical Limits
  48. GRB050815: Swift XRT afterglow localization
  49. GRB050815: Swift-BAT detection of a burst
  50. GRB050814: Fading red source
  51. GRB 050813: Gemini Spectra Revisited
  52. GRB050814: P60 Optical Afterglow Candidate
  53. GRB 050814: XRT refined analysis
  54. GRB050814: SWIFT/UVOT observation
  55. GRB050814: Refined analysis of the Swift-BAT burst
  56. GRB 050813: Gemini spectroscopy and redshifts of galaxies B and C
  57. GRB 050814: Swift XRT Afterglow Localization
  58. GRB 050814: Swift detection of a burst
  59. GRB 050813: Magellan detection of a high redshift galaxy cluster
  60. GRB 050813: I-band observations
  61. GRB050813, SDSS pre-burst observations
  62. GRB 050813: KAIT optical limit
  63. GRB 050813: Swift-BAT refined analysis
  64. GRB 050813: Photometry of object in XRT error circle
  65. GRB050813: SWIFT/UVOT observation
  66. GRB 050813: Swift XRT afterglow localization
  67. GRB 050813: Possible Short Swift-BAT GRB
  68. GRB050813 (Swift 150139): P60 Observations
  69. Swift-BAT trigger 150131 is not a GRB
  70. GRB050803: CrAO optical observations, no OT candidate
  71. GRB 050803: PROMPT BVRcIc Observations
  72. GRB050805b: CrAO optical limit
  73. GRB050805a : Null detection report
  74. GRB050803, optical observations
  75. Swift-BAT trigger 149118 is very likely not a GRB
  76. Retraction of Swift Trigger 149131 (GRB 050805B)
  77. GRB 050805b: OHP optical limits
  78. GRB 050805b: TAROT optical limits
  79. GRB050805b: MASTER optical observations
  80. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  81. GRB050805a: MASTER optical candidat
  82. Swift-BAT trigger 149118 is probably not a GRB
  83. GRB 050803: RTT150 optical observations
  84. GRB050803: CrAO optical observations, possible OT candidate
  85. GRB050803: Optical/UV Upper Limits from Swift-UVOT
  86. GRB 050803: Keck Observations
  87. GRB 050803: Swift-BAT refined analysis
  88. GRB050803: MASTER further analys
  89. GRB 050803: Magellan Observations
  90. GRB 050803: early Swift XRT analysis results
  91. GRB 050803: TAROT optical limits
  92. GRB050803: MASTER optical observations
  93. GRB050803: Swift-BAT detection of a very long burst
  94. GCN GRB observation 050713A
  95. GRB 050802: Swift/UVOT optical and UV detections
  96. GRB050802 radio non-detection
  97. GRB 050730: OHP optical observations
  98. GRB 050802: early Swift XRT analysis results
  99. GRB 050802: Swift/UVOT observations
  100. GRB 050802: Swift-BAT refined analysis

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