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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"

24376 results found.

  1. GRB 050315: Swift-BAT further refined analysis
  2. GRB 050315 I-band observations
  3. GRB050315: Radio afterglow
  4. GRB050315: Swift-BAT Refined analysis
  5. GRB 050219b: Gemini/GNIRS near-infrared spectroscopy
  6. Swift-BAT detection of GRB 050315
  7. GRB050309: CONCAM pre-trigger and trigger coincident optical
  8. GRB 050306: optical afterglow
  9. Swift-BAT trigger 107873: No Swift XRT counterpart
  10. GRB 050306: Confirmation of X-ray afterglow
  11. GRB 050309, Early optical limits from RAPTOR
  12. GRB050309: Early optical limit from P60
  13. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  14. GRB 050306: CORRECTION to date of observation
  15. GRB 050306: No Swift UVOT Optical Counterpart Detected
  16. GRB 050306: REM optical-infrared observations
  17. GRB 050306: Possible X-ray Afterglow Position from the Swift
  18. GRB 050306,optical observation
  19. GRB 050306: Swift-BAT detection of a long burst
  20. Ongoing activity of SGR 1806-20 after the giant flare
  21. GRB050215B: Late-Time Swift UVOT Observations
  22. PROMPT VRcIc Observations of GRB 050223
  23. IBAS GRB Alert #2321
  24. INTEGRAL detection of GRB 050223
  25. GRB 050223 Swift/BAT detection of a burst
  26. GRB 050223: Swift XRT Position
  27. GRB050219b: CORRECTION to time of UVOT observations
  28. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  29. GRB 050219b: Swift-BAT detection of a burst
  30. GRB 050219: Swift-BAT detection of a burst
  31. GRB050215b: Swift UVOT Detection of Afterglow Emission
  32. GRB050215b: P60 Optical Observations
  33. GRB 050215b: Swift XRT Observations
  34. Swift-BAT detects two bursts: GRB050215a and GRB050215b
  35. GRB 050215b, BOOTES-1B optical limit
  36. GRB050209: REM optical observations
  37. GRB 050209 Optical observations
  38. GRB050209: P60 Optical Observations
  39. Further analysis of the short Swift-BAT GRB 050202
  40. GRB 050129: Optical observations
  41. GRB 050202: Optical observations with LCO40
  42. GRB 050128 Optical observation with REM
  43. GRB 050129: a weak long GRB detected with INTEGRAL
  44. GRB050128: Faulkes Telescope South observations
  45. GRB050128,optical observations
  46. GRB050126: Updated Swift XRT Position
  47. GRB050126: MASTER optical limit for KECK OT
  48. GRB050126: MASTER optical observations
  49. GRB 050126: Prompt XRT detection and localization
  50. GRB 050124 I-band observation
  51. GRB050124,optical observation
  52. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  53. GRB050123,optical observation
  54. GRB050123: P60 Observations
  55. GRB 050123(=H3666): A GRB Localized in Real Time by HETE
  56. Unusual optical transient (GRB ???)
  57. GRB050117a: Refined analysis
  58. GRB050117: Palomar WIRC Ks-band observations
  59. GRB050117: Refined XRT position
  60. GRB050117: MASTER optical observations
  61. MASTER:GRB050117 SWIFT
  62. GRB050117: Swift-BAT detection of a long multi-peaked burst
  63. Triangulation of Short Hard GRB050112 (large error box)
  64. SGR1806: Optical Transient Candidates in SOHO/LASCO Images
  65. Further ATCA observations of SGR 1806-20
  66. SGR 1806-20: Low frequency GMRT results; submission to GCN circulars
  67. SGR 1806-20, RHESSI observations of the 041227 giant flare
  68. Third epoch observations of SGR 1806-20 with VLA
  69. Second-epoch VLA observations of SGR 1806-20
  70. SGR1806 VLA Observations
  71. GRB041219, early time observations
  72. Detection of the SGR 1806-20 giant outburst back-scattered by the
  73. The giant outburst from SGR 1806-20
  74. IPN localization of giant flare from SGR1806-20
  75. Giant flare from SGR 1806-20 detected by INTEGRAL
  76. GRB041219; RXTE ASM Observations
  77. Swift-BAT Time History of GRB041219
  78. GRB 041219c: PROMPT Observations
  79. GRB 041218: optical observations
  80. Very high activity of SGR 1806-20
  81. GRB 041219 : optical follow-up observations
  82. GRB 041218 Optical Observations
  83. GRB 041219 Optical Observations
  84. GRB041219: Continued NIR Observations
  85. GRB 041219 ,optical observation
  86. GRB 041218: R-band optical observations
  87. GRB041218: Liverpool Telescope optical observations
  88. GRB041218: Continued P60 Optical Observations
  89. GRB 041219: Infrared Afterglow Candidate
  90. GRB 041219: Infrared Afterglow Candidate
  91. GRB 041219 - A long GRB detected by INTEGRAL
  92. GRB 041217: PROMPT Observations
  93. GRB 041218 - A long GRB detected by integral
  94. GRB041217: Infrared Observations
  95. GRB041217: The First GRB Located On-Board Swift
  96. GRB041211: Faulkes Telescope continued optical monitoring
  97. GRB041211: Continued P60 Observations
  98. GRB041211: Ashra Prototype optical observation
  99. GRB041211, Faulkes Telescope optical observation
  100. GRB041211,optical observation

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