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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"

18495 results found.

  1. GRB 060604 optical photometry
  2. GRB 060604: Swift-XRT Team refined analysis
  3. GRB 060604: BAT refined analysis
  4. GRB 060604A: ROTSE-III Optical Limits
  5. GRB 060604: Swift detection of a burst with possible optical counterpart
  6. GRB 060602A: Swift-BAT Refined Analysis: Correction
  7. GRB 060602B: XMM-Newton Survey Source
  8. GRB 060602B: Swift-XRT Refined Analysis
  9. GRB 060602B: Swift-BAT Refined Analysis
  10. GRB 060602B: Swift/UVOT observations
  11. GRB 060602A: Swift-BAT Refined Analysis
  12. GRB 060602B: RTT150 optical observations
  13. GRB 060602B: Swift detection of a burst
  14. GRB060602 - SDSS Pre-Burst Observations
  15. GRB 060602: Swift detection of a burst
  16. GRB 060526: Break in X-ray light curve
  17. GRB 051227 : WIDGET simultaneous optical observations
  18. GRB 060526: Multiple Optical Flares
  19. GRB060502b: optical observations
  20. GRB 060526: Optical Flare
  21. GRB 060526: Refined analysis of the Swift-BAT burst
  22. GRB 060526: RTT150 optical observations
  23. GRB060526: Further Swift-UVOT Observations
  24. GRB 060526: Swift/XRT Team refined analysis
  25. GRB 060526: ROTSE-III Observations of Optical Counterpart
  26. GRB 060526: Watcher Observations
  27. GRB 060526: Continued emission for the Swift burst
  28. GRB 060526: Swift detection of a burst with x-ray and optical afterglow
  29. GRB 060413 : WIDGET simultaneous optical observations
  30. GRB 060522: Swift/UVOT Observations: Correction
  31. GRB 060522: Swift/UVOT Observations of the Optical Afterglow
  32. XMM-Newton observation of GRB060510b
  33. GRB 060522: Swift/XRT Team refined analysis
  34. GRB 060522: Swift-BAT Refined Analysis
  35. GRB 060522: Swift detection of a burst with possible optical afterglow
  36. GRB 060210: Jet Break in the XRT light curve
  37. GRB 060516: Refined analysis of the Swift-BAT burst
  38. GRB 060516: Swift detection of a burst
  39. GRB 060505 BAT refined analysis
  40. GRB 060515 BAT refined analysis
  41. GRB 060512: TAROT optical observation
  42. GRB 060515: Swift/XRT Team refined analysis
  43. GRB 060515: Swift/UVOT Upper Limits
  44. GRB 060515: Swift/XRT position
  45. GRB 060515: Super-LOTIS Observations
  46. GRB060515: Swift/UVOT initial observation
  47. GRB 060515: TAROT optical observation
  48. GRB 060515: ROTSE-III Optical Limits
  49. GRB 060515: Swift detection of a burst
  50. Swift/UVOT observations of GRB060512.
  51. GRB060512: Swift XRT Team refined analysis
  52. GRB 060512: Detection of NIR afterglow
  53. GRB 060512: Swift-BAT Refined Analysis
  54. GRB060512 Name Correction: LT Afterglow detection
  55. GRB060512: Liverpool Telescope Afterglow detection
  56. GRB 060512: Swift detection of a burst with an optical afterglow
  57. GRB 060510A: Swift/UVOT Detection of an Optical Afterglow
  58. GRB 060505: X-ray afterglow - Correction -
  59. GRB 060505: X-ray afterglow
  60. Konus-Wind observation of GRB 060510A
  61. GRB 060428a, SMARTS optical/IR afterglow detection
  62. GRB060510B: Swift XRT refined analysis
  63. GRB 060510B: Swift/UVOT Upper Limits
  64. GRB 060510A: Refined analysis of the Swift-BAT burst
  65. GRB 060510B: Swift-BAT Refined Analysis
  66. GRB060510A: XRT refined analysis
  67. GRB 060510B: Super-LOTIS Observations
  68. GRB 060510B: MDM Observations and candidate OT
  69. GRB 060510B: Swift detection of a burst
  70. GRB 060510: Swift detection of a burst with optical transient
  71. GRB060502B: improvement in the XRT afterglow position
  72. GRB 060507: BART limit
  73. GRB 060507: Final Refined analysis of the Swift-BAT burst
  74. GRB 060507: Swift-BAT Refined Analysis
  75. GRB 060507: Swift/UVOT Upper Limits
  76. GRB 060507: Swift XRT Team Refined Analysis
  77. GRB 060507: MDM Optical Upper Limit
  78. GRB060507: Swift XRT position
  79. GRB 060507: Swift detection of a burst
  80. GRB060505: Swift/UVOT Observations
  81. GRB 060505: Swift XRT Team Refined Analysis
  82. GRB 060505: Swift XRT afterglow canditate position
  83. GRB 060505: Swift-BAT detection of a weak burst
  84. GRB 060502B MDM Follow-up Observation
  85. GRB060502A, optical observation
  86. GRB 060502B: Swift/UVOT upper limits
  87. GRB 060502A: Swift/UVOT source detection
  88. GRB 060502B: MDM Optical Observation
  89. GRB 060502B: Refined analysis of the Swift-BAT short burst
  90. GRB060502B: Swift XRT Team refined analysis
  91. GRB060502B: correction to XRT position
  92. GRB 060502B: MASTER optical observations
  93. GRB 060502B: Swift detection of a short burst
  94. GRB060502: Swift-XRT refined analysis
  95. GRB 060502: Swift-BAT refined analysis
  96. GRB 060502: APO Spectroscopic Observations
  97. GRB060501: Swift UVOT followup observations
  98. GRB060502: Super-LOTIS Observations
  99. GRB 060502: Swift detection of a burst with an optical counterpart
  100. GRB 060501: MDM Observations

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