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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"

25841 results found.

  1. GRB050904: P60 Observations
  2. GRB 050904: TAROT optical limits
  3. GRB 050827: Swift XRT preliminary analysis results
  4. GRB 050827 : OSN 1.5m optical observations
  5. GRB 050827: P200 NIR Observations
  6. GRB050827: Swift/UVOT upper limits
  7. GRB 050827: Optical Limit
  8. GRB 050827: XRT possible afterglow detection
  9. GRB050824: Maidanak optical limits
  10. GRB050827: RTT150 optical observations
  11. GRB 050827: Swift-BAT refined analysis
  12. GRB050827: Swift-BAT detection of a burst
  13. Subaru Observations of GRB050724
  14. GRB050824, HETE-2 Observation
  15. GRB 050826: Swift XRT preliminary analysis results
  16. GRB 050826: BAT refined analysis
  17. GRB050826: Swift/UVOT early upper limits
  18. GRB050824: First 2 hours of power low optical decay?
  19. GRB050826: Swift-BAT detection of a long burst
  20. GRB050824: CORRECTION to UVOT observing times
  21. Swift-BAT trigger 152038 is probably not a GRB
  22. GRB050824: Swift/UVOT detection of fading afterglow
  23. GRB050824: decay of the XRT light curve and updated X-ray spectrum
  24. GRB050824, I-band imaging
  25. GRB 050822: refined XRT analysis
  26. GRB 050824: XRT refined analysis and possible afterglow detection
  27. GRB 050824: BAT refined analysis of a soft weak burst
  28. GRB050824: MASTER:OT decay
  29. GRB050824: MASTER observation OT
  30. GRB050805a: MASTER optical candidat
  31. XRF050509c: Radio upper limits from GMRT
  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. Swift/UVOT UV Photometry of GRB 050820B
  39. GRB 050822: Swift detection of a long burst
  40. GRB050820a BVRcIc field photometry
  41. GRB050820B XMM-Newton observation
  42. GRB 050820a: NIR Observations by WIRO
  43. GRB 050820B: Swift XRT position
  44. GRB050820B: Refined analysis of the Swift-BAT burst
  45. GRB050820B: BAT-Swift detection of a bright GRB
  46. GRB050820: refined XRT analysis
  47. GRB 050820 Swift-BAT refined analysis
  48. GRB050819: refined XRT analysis
  49. GRB 050820: Swift detection of a GRB
  50. GRB 050819 Swift-BAT refined analysis
  51. GRB050819: Swift-BAT detection of a weak burst
  52. GRB 050817: Optical observations
  53. GRB050817: Swift-BAT Detection of a burst
  54. GRB 050814: continued fading
  55. GRB050815: XRT refined analysis
  56. GRB050815: Refined analysis of the Swift-BAT burst
  57. GRB 050815: ROTSE-III Optical Limits
  58. GRB050815: Swift-BAT detection of a burst
  59. GRB050814: Fading red source
  60. GRB050814: P60 Optical Afterglow Candidate
  61. GRB 050813: Non-fading of afterglow candidate
  62. GRB 050814: XRT refined analysis
  63. GRB050814: SWIFT/UVOT observation
  64. GRB050814: Refined analysis of the Swift-BAT burst
  65. GRB 050813: Gemini spectroscopy and redshifts of galaxies B and C
  66. GRB 050814: Swift XRT Afterglow Localization
  67. GRB 050814: Swift detection of a burst
  68. GRB 050813: Magellan detection of a high redshift galaxy cluster
  69. GRB050813, SDSS pre-burst observations
  70. GRB050813: SWIFT/UVOT observation
  71. GRB 050813: Swift XRT afterglow localization
  72. GRB050807(=H3889): An X-Ray Rich GRB Localized by HETE
  73. GRB 050730: WSRT Radio Observations
  74. GRB050805b: CrAO optical limit
  75. GRB050805a : Null detection report
  76. GRB050730, optical observations
  77. GRB050803, optical observations
  78. Retraction of Swift Trigger 149131 (GRB 050805B)
  79. GRB 050805b: OHP optical limits
  80. GRB 050805b: TAROT optical limits
  81. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  82. GRB050805a: MASTER optical candidat
  83. GRB050802: TNG optical observations
  84. GRB050803: Radio Observation
  85. GRB 050803: RTT150 optical observations
  86. GRB050801: Radio Observation
  87. GRB050730: Radio Detection
  88. GRB 050803: Keck Observations
  89. GRB 050803: Swift-BAT refined analysis
  90. GRB 050802.422: Fading of the afterglow and detection of the host
  91. GRB 050803: early Swift XRT analysis results
  92. GRB 050803: TAROT optical limits
  93. GCN GRB observation 050713A
  94. GRB050730: FORS1 and UVES/VLT low- and high-resolution spectroscopy
  95. GRB 050802: Swift/UVOT optical and UV detections
  96. GRB050802: CrAO optical observations
  97. GRB050802 radio non-detection
  98. GRB 050730: OHP optical observations
  99. GRB 050802: early Swift XRT analysis results
  100. GRB 050802: Swift/UVOT observations

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