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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"

36053 results found.

  1. GRB 050826: Optical Candidate
  2. GRB050824, HETE-2 Observation
  3. GRB 050826: Swift XRT preliminary analysis results
  4. GRB 050826: BAT refined analysis
  5. GRB050824: First 2 hours of power low optical decay?
  6. GRB 050826: Swift XRT position
  7. GRB050826: Swift-BAT detection of a long burst
  8. GRB050824: MASTER final analysis of the OT observations
  9. Possible GRB050825:MASTER optical observations
  10. Swift-BAT trigger 152038 is definitely not a GRB
  11. Swift-BAT trigger 152038 is probably not a GRB
  12. GRB050824: decay of the XRT light curve and updated X-ray spectrum
  13. GRB050824, I-band imaging
  14. GRB050824: Radio Observations
  15. GRB 050824: Spectroscopic redshift from the VLT
  16. GRB 050822: refined XRT analysis
  17. GRB 050824: XRT refined analysis and possible afterglow detection
  18. GRB 050824: BAT refined analysis of a soft weak burst
  19. GRB050824: MASTER:OT decay
  20. GRB050824: MASTER observation OT
  21. GRB050805a: MASTER optical candidat
  22. GRB 050824: ROTSE-III Optical Limits
  23. GRB050824: Swift-BAT detection of a burst
  24. GRB 050824 optical candidate
  25. GRB050820A: RTT150 optical observations
  26. GRB050820a: PROMPT RcIc Observations
  27. GRB050815: Maidanak optical observation
  28. XRF050509c: Radio upper limits from GMRT
  29. VLT/UVES spectroscopy of GRB050820
  30. GRB 050820A BAT observations of second, larger episode of emission
  31. GRB050813: Maidanak I-band observations
  32. GRB 050822: Swift-BAT refined analysis
  33. GRB050525, GRB050607, GRB050802 BVRcIc field photometry
  34. GRB050820B at FRAM
  35. GRB050820A: RTT150 optical observations
  36. GRB 050820a - corrections to GCN 3846
  37. Swift/UVOT UV Photometry of GRB 050820B
  38. GRB 050822: ROTSE-III Prompt Optical Limits
  39. GRB 050822: Swift detection of a long burst
  40. Correction to Eiso calculation in GCN 3835 on GRB 050820A
  41. GRB050820A: Radio Observation
  42. GRB050825a - very long GRB like GRB041219a? (Konus-Wind observation)
  43. GRB050820a BVRcIc field photometry
  44. GRB 050820a: NIR Observations by WIRO
  45. GRB 050820B: Swift XRT position
  46. GRB050820B: Refined analysis of the Swift-BAT burst
  47. GRB050820B: BAT-Swift detection of a bright GRB
  48. GRB050820: refined XRT analysis
  49. GRB 050820: Early RAPTOR detections
  50. GRB 050820 Swift-BAT refined analysis
  51. GRB 050820: P60 Temporal Decay Index
  52. GRB 050820: High Resolution Spectroscopy from Keck
  53. GRB050819: RTT150 optical observations
  54. GRB 050820: Swift detection of a GRB
  55. GRB 050819 Swift-BAT refined analysis
  56. GRB050819: Swift XRT position
  57. GRB050819: Swift-BAT detection of a weak burst
  58. Swift-BAT trigger 150993 is not a GRB
  59. Swift Trigger 150823 is HETE J1900.1-2455
  60. GRB 050817: Optical observations
  61. GRB 050815: Radio Observation
  62. GRB050814: Radio Observation
  63. GRB050817: Negative Optical Observations
  64. GRB 050814: continued fading
  65. GRB 050813: Radio Observations
  66. GRB050815: Refined analysis of the Swift-BAT burst
  67. GRB 050815: ROTSE-III Optical Limits
  68. GRB050815: Swift XRT afterglow localization
  69. GRB 050730: Third Epoch WSRT Radio Observations
  70. GRB050814: Fading red source
  71. GRB 050813: Gemini Spectra Revisited
  72. GRB 050813: Non-fading of afterglow candidate
  73. GRB 050814: XRT refined analysis
  74. GRB050814: Refined analysis of the Swift-BAT burst
  75. GRB050813: Gemini Imaging
  76. GRB 050813: Gemini spectroscopy and redshifts of galaxies B and C
  77. GRB 050814: Swift XRT Afterglow Localization
  78. GRB 050814: Swift detection of a burst
  79. GRB 050813: Magellan detection of a high redshift galaxy cluster
  80. GRB050813: RTT150 optical observations
  81. GRB 050813: I-band observations
  82. GRB050813, SDSS pre-burst observations
  83. GRB 050813: KAIT optical limit
  84. GRB 050813: Swift-BAT refined analysis
  85. GRB 050813: Photometry of object in XRT error circle
  86. GRB 050813: Swift XRT afterglow localization
  87. RBO GRB 050714A and GRB 050716 observations
  88. GRB 050813: Possible Short Swift-BAT GRB
  89. Swift-BAT trigger 150131 is not a GRB
  90. GRB050807(=H3889): An X-Ray Rich GRB Localized by HETE
  91. Ongoing activity of SGR 1806-20: an intermediate burst 050811
  92. GRB050803: CrAO optical observations, no OT candidate
  93. GRB 050730: WSRT Radio Observations
  94. GRB 050803: PROMPT BVRcIc Observations
  95. GRB 050807: ROTSE-III Optical Limits
  96. GRB 050730, optical observation
  97. GRB050805b: CrAO optical limit
  98. GRB050805a : Null detection report
  99. GRB050730, optical observations
  100. GRB050803, optical observations

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