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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"

27810 results found.

  1. GRB 060515 BAT refined analysis
  2. GRB 060512: TAROT optical observation
  3. GRB 060515: Swift/XRT Team refined analysis
  4. GRB 060515: Swift/UVOT Upper Limits
  5. GRB 060515: Swift/XRT position
  6. GRB 060515: Super-LOTIS Observations
  7. GRB060515: Swift/UVOT initial observation
  8. GRB 060515: TAROT optical observation
  9. GRB 060515: ROTSE-III Optical Limits
  10. GRB 060515: Swift detection of a burst
  11. Swift/UVOT observations of GRB060512.
  12. GRB 060512: Subaru NIR observation
  13. GRB060512: Swift XRT Team refined analysis
  14. GRB 060512: Detection of NIR afterglow
  15. GRB 060512: P60 Observations
  16. GRB 060512: Swift-BAT Refined Analysis
  17. GRB060512 Name Correction: LT Afterglow detection
  18. GRB060512: Liverpool Telescope Afterglow detection
  19. GRB 060512: Swift detection of a burst with an optical afterglow
  20. GRB 060510A: Swift/UVOT Detection of an Optical Afterglow
  21. GRB 060505: X-ray afterglow - Correction -
  22. GRB 060505: X-ray afterglow
  23. Konus-Wind observation of GRB 060510A
  24. GRB 060428a, SMARTS optical/IR afterglow detection
  25. GRB060510B: Swift XRT refined analysis
  26. GRB 060510B: Swift/UVOT Upper Limits
  27. GRB 060510A: Refined analysis of the Swift-BAT burst
  28. GRB 060510B: Swift-BAT Refined Analysis
  29. GRB060510A: XRT refined analysis
  30. GRB060510B : Faulkes North Telescope detection
  31. GRB 060510B: Super-LOTIS Observations
  32. GRB 060510B: MDM Observations and candidate OT
  33. GRB 060510B: Swift detection of a burst
  34. GRB 060510: Swift detection of a burst with optical transient
  35. GRB060507: optical afterglow detection
  36. GRB060502B: improvement in the XRT afterglow position
  37. GRB 060507: BART limit
  38. GRB 060507: Final Refined analysis of the Swift-BAT burst
  39. GRB 060507: Swift-BAT Refined Analysis
  40. GRB 060507: Swift/UVOT Upper Limits
  41. GRB 060507: Swift XRT Team Refined Analysis
  42. GRB 060507: MDM Optical Upper Limit
  43. GRB060507: Swift XRT position
  44. GRB 060507: Swift detection of a burst
  45. GRB060505: Swift/UVOT Observations
  46. GRB 060505: Swift XRT Team Refined Analysis
  47. GRB 060505: Swift XRT afterglow canditate position
  48. GRB 060505: Swift-BAT detection of a weak burst
  49. GRB 060502B MDM Follow-up Observation
  50. GRB060502A, optical observation
  51. GRB 060502B: Swift/UVOT upper limits
  52. GRB 060502A: Swift/UVOT source detection
  53. GRB 060502B: MDM Optical Observation
  54. GRB 060502B: Refined analysis of the Swift-BAT short burst
  55. GRB060502B: Swift XRT Team refined analysis
  56. GRB060502B: correction to XRT position
  57. GRB 060502B: MASTER optical observations
  58. GRB 060502B: Swift detection of a short burst
  59. GRB060502: Swift-XRT refined analysis
  60. GRB 060502: Swift-BAT refined analysis
  61. GRB 060502: APO Spectroscopic Observations
  62. GRB060501: Swift UVOT followup observations
  63. GRB060502: Super-LOTIS Observations
  64. GRB 060502: Swift detection of a burst with an optical counterpart
  65. GRB 060501: MDM Observations
  66. GRB060501: Super-LOTIS observations
  67. GRB060501: P60 imaging and afterglow candidate
  68. GRB 060501: Refined analysis of the Swift-BAT burst
  69. GRB060501: Swift XRT position
  70. GRB 060501: ROTSE-III Optical Limits
  71. GRB 060501: Swift detection of a burst
  72. GRB060428B: optical observation
  73. GRB060428B: possible detection of an optical counterpart by Swift/UVOT.
  74. GRB 060428B: MDM Observations
  75. GRB060428B: Swift XRT Team refined analysis
  76. GRB 060427B: IPN localization of a short hard burst
  77. GRB 060428B: Refined analysis of the Swift-BAT burst
  78. GRB 060428B: KAIT observations
  79. GRB 051117A: Bright host galaxy not confirmed
  80. GRB060428A: Swift/UVOT observations.
  81. GRB060428B, optical observation
  82. GRB 060428A: Refined analysis of the Swift-BAT burst
  83. GRB060428A: Swift XRT Team refined analysis
  84. GRB 060428B: Swift detection of a burst
  85. GRB 060428: Swift detection of a burst
  86. GRB 060427: NOT observations
  87. GRB 060427: Swift/UVOT upper limits.
  88. GRB 060427: Refined analysis of the Swift-BAT burst
  89. GRB060427: Swift XRT Team refined analysis
  90. GRB060418: Swift XRT Team Further Refined Analysis
  91. GRB 060427, optical observation
  92. GRB 060427: Swift detection of a burst
  93. GRB 060425: IPN localization and KW spectrum of a short, hard burst
  94. GRB060424: optical afterglow detection
  95. GRB060418: Further Analysis of MIKE Spectroscopy
  96. GRB 060424: Refined analysis of the Swift-BAT burst
  97. GRB 060424: Swift detection of a burst
  98. OT 060420: Likely Not a New Cosmic Transient
  99. Swift-BAT detection of Mrk 421
  100. OT 060420: CONCAM detection of a candidate new magnitude 5 optical

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