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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"

32541 results found.

  1. GRB050824: Maidanak optical limits
  2. GRB050820A: RTT150 optical observations
  3. GRB050827: RTT150 optical observations
  4. GRB 050827: Swift-BAT refined analysis
  5. GRB 050826: Optical Candidate
  6. GRB050824, HETE-2 Observation
  7. GRB 050826: Swift XRT preliminary analysis results
  8. GRB 050826: BAT refined analysis
  9. GRB050826: Swift/UVOT early upper limits
  10. GRB050824: First 2 hours of power low optical decay?
  11. GRB 050826: Swift XRT position
  12. GRB050824: MASTER final analysis of the OT observations
  13. GRB050824: CORRECTION to UVOT observing times
  14. GRB050824: Swift/UVOT detection of fading afterglow
  15. GRB050824: decay of the XRT light curve and updated X-ray spectrum
  16. GRB050824: Radio Observations
  17. GRB 050824: Spectroscopic redshift from the VLT
  18. GRB 050822: refined XRT analysis
  19. GRB 050824: BAT refined analysis of a soft weak burst
  20. GRB050824: MASTER:OT decay
  21. GRB050824: MASTER observation OT
  22. GRB050805a: MASTER optical candidat
  23. GRB 050824: ROTSE-III Optical Limits
  24. GRB050820A: RTT150 optical observations
  25. GRB050820a: PROMPT RcIc Observations
  26. GRB050815: Maidanak optical observation
  27. XRF050509c: Radio upper limits from GMRT
  28. VLT/UVES spectroscopy of GRB050820
  29. GRB050822: Swift/UVOT upper limits
  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. GRB050820A: RTT150 optical observations
  34. GRB 050820a - corrections to GCN 3846
  35. Swift/UVOT UV Photometry of GRB 050820B
  36. GRB 050822: ROTSE-III Prompt Optical Limits
  37. Correction to Eiso calculation in GCN 3835 on GRB 050820A
  38. GRB050820A: Radio Observation
  39. GRB050825a - very long GRB like GRB041219a? (Konus-Wind observation)
  40. GRB050820a BVRcIc field photometry
  41. GRB 050820a: NIR Observations by WIRO
  42. GRB 050820B: Swift XRT position
  43. GRB050820B: Refined analysis of the Swift-BAT burst
  44. Swift/UVOT photometry of GRB050820
  45. GRB050820: refined XRT analysis
  46. GRB 050820: Early RAPTOR detections
  47. GRB 050820 Swift-BAT refined analysis
  48. GRB 050820: P60 Temporal Decay Index
  49. GRB 050820: High Resolution Spectroscopy from Keck
  50. GRB050819: refined XRT analysis
  51. GRB050819: RTT150 optical observations
  52. GRB 050820: Swift detection of a GRB
  53. GRB 050819 Swift-BAT refined analysis
  54. GRB050819: Swift XRT position
  55. Swift-BAT trigger 150993 is not a GRB
  56. Swift Trigger 150823 is HETE J1900.1-2455
  57. GRB 050817: Optical observations
  58. GRB 050815: Radio Observation
  59. GRB050814: Radio Observation
  60. GRB050817: Negative Optical Observations
  61. GRB 050814: continued fading
  62. GRB050815: XRT refined analysis
  63. GRB 050813: Radio Observations
  64. GRB050815: Refined analysis of the Swift-BAT burst
  65. GRB 050815: ROTSE-III Optical Limits
  66. GRB050815: Swift XRT afterglow localization
  67. GRB 050730: Third Epoch WSRT Radio Observations
  68. GRB050814: Fading red source
  69. GRB 050813: Gemini Spectra Revisited
  70. GRB050814: P60 Optical Afterglow Candidate
  71. GRB 050813: Non-fading of afterglow candidate
  72. GRB 050814: XRT refined analysis
  73. GRB050814: SWIFT/UVOT observation
  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. GRB050813: SWIFT/UVOT observation
  87. GRB 050813: Swift XRT afterglow localization
  88. RBO GRB 050714A and GRB 050716 observations
  89. Swift-BAT trigger 150131 is not a GRB
  90. GRB050807(=H3889): An X-Ray Rich GRB Localized by HETE
  91. GRB050803: CrAO optical observations, no OT candidate
  92. GRB 050730: WSRT Radio Observations
  93. GRB 050803: PROMPT BVRcIc Observations
  94. GRB 050807: ROTSE-III Optical Limits
  95. GRB 050730, optical observation
  96. GRB050805a : Null detection report
  97. GRB050730, optical observations
  98. GRB050803, optical observations
  99. GRB 050805b: TAROT optical limits
  100. GRB050802: TNG optical observations

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