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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"

42172 results found.

  1. GRB 050827: Swift-BAT refined analysis
  2. GRB050827: Swift-BAT detection of a burst
  3. Subaru Observations of GRB050724
  4. GRB 050826: Optical Candidate
  5. GRB050824, HETE-2 Observation
  6. GRB 050826: Swift XRT preliminary analysis results
  7. GRB 050826: BAT refined analysis
  8. GRB050826: Swift/UVOT early upper limits
  9. GRB050824: First 2 hours of power low optical decay?
  10. GRB 050826: Swift XRT position
  11. GRB050826: Swift-BAT detection of a long burst
  12. Possible GRB050825:MASTER optical observations
  13. GRB050824: CORRECTION to UVOT observing times
  14. Swift-BAT trigger 152038 is probably not a GRB
  15. GRB050824: Swift/UVOT detection of fading afterglow
  16. GRB050824: decay of the XRT light curve and updated X-ray spectrum
  17. GRB050824, I-band imaging
  18. GRB050824: Radio Observations
  19. GRB 050822: refined XRT analysis
  20. GRB 050824: XRT refined analysis and possible afterglow detection
  21. GRB 050824: BAT refined analysis of a soft weak burst
  22. GRB050824: MASTER:OT decay
  23. GRB050824: MASTER observation OT
  24. GRB050805a: MASTER optical candidat
  25. GRB 050824: ROTSE-III Optical Limits
  26. GRB050824: Swift-BAT detection of a burst
  27. GRB 050824 optical candidate
  28. GRB050820A: RTT150 optical observations
  29. GRB050815: Maidanak optical observation
  30. XRF050509c: Radio upper limits from GMRT
  31. VLT/UVES spectroscopy of GRB050820
  32. GRB050822: Swift/UVOT upper limits
  33. GRB 050820A BAT observations of second, larger episode of emission
  34. GRB050813: Maidanak I-band observations
  35. GRB 050822: Swift-BAT refined analysis
  36. GRB050525, GRB050607, GRB050802 BVRcIc field photometry
  37. GRB050820B at FRAM
  38. GRB050820A: RTT150 optical observations
  39. GRB 050820a - corrections to GCN 3846
  40. GRB 050822: ROTSE-III Prompt Optical Limits
  41. GRB 050822: Swift detection of a long burst
  42. GRB050820A: Radio Observation
  43. GRB050825a - very long GRB like GRB041219a? (Konus-Wind observation)
  44. GRB050820a BVRcIc field photometry
  45. GRB050820B XMM-Newton observation
  46. GRB 050820a: NIR Observations by WIRO
  47. GRB 050820B: Swift XRT position
  48. GRB050820B: Planned XMM-Newton observation
  49. GRB050820B: Refined analysis of the Swift-BAT burst
  50. GRB050820B: BAT-Swift detection of a bright GRB
  51. GRB050820: refined XRT analysis
  52. GRB 050820 Swift-BAT refined analysis
  53. GRB 050820: P60 Temporal Decay Index
  54. GRB 050820: High Resolution Spectroscopy from Keck
  55. GRB050819: refined XRT analysis
  56. GRB050819: RTT150 optical observations
  57. GRB 050820: Swift detection of a GRB
  58. GRB050820: Optical afterglow from P60
  59. GRB 050819 Swift-BAT refined analysis
  60. GRB050819: Swift XRT position
  61. GRB050819: Swift-BAT detection of a weak burst
  62. Swift-BAT trigger 150993 is not a GRB
  63. Swift Trigger 150823 is HETE J1900.1-2455
  64. GRB 050817: Optical observations
  65. GRB 050815: Radio Observation
  66. GRB050814: Radio Observation
  67. GRB050817: Negative Optical Observations
  68. GRB050817: Swift-BAT Detection of a burst
  69. GRB 050814: continued fading
  70. GRB050815: Optical afterglow detection by Swift UVOT
  71. GRB050815: XRT refined analysis
  72. GRB050815: Refined analysis of the Swift-BAT burst
  73. GRB 050815: ROTSE-III Optical Limits
  74. GRB050815: Swift XRT afterglow localization
  75. GRB050815: Swift-BAT detection of a burst
  76. GRB 050730: Third Epoch WSRT Radio Observations
  77. GRB050814: Fading red source
  78. GRB 050813: Gemini Spectra Revisited
  79. GRB050814: P60 Optical Afterglow Candidate
  80. GRB 050813: Non-fading of afterglow candidate
  81. GRB 050814: XRT refined analysis
  82. GRB050814: SWIFT/UVOT observation
  83. GRB050814: Refined analysis of the Swift-BAT burst
  84. GRB050813: Gemini Imaging
  85. GRB 050813: Gemini spectroscopy and redshifts of galaxies B and C
  86. GRB 050814: Swift XRT Afterglow Localization
  87. GRB 050814: Swift detection of a burst
  88. GRB 050813: Magellan detection of a high redshift galaxy cluster
  89. GRB050813: RTT150 optical observations
  90. GRB 050813: I-band observations
  91. GRB050813, SDSS pre-burst observations
  92. GRB 050813: KAIT optical limit
  93. GRB050813: SWIFT/UVOT observation
  94. GRB 050813: Swift XRT afterglow localization
  95. RBO GRB 050714A and GRB 050716 observations
  96. GRB 050813: Possible Short Swift-BAT GRB
  97. Swift-BAT trigger 150131 is not a GRB
  98. GRB050807(=H3889): An X-Ray Rich GRB Localized by HETE
  99. Ongoing activity of SGR 1806-20: an intermediate burst 050811
  100. GRB050803: CrAO optical observations, no OT candidate

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