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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"

24378 results found.

  1. GRB050316: MASTER before, simultanious and follow up optical
  2. GRB050316: MASTER optical observations
  3. GRB 050315: Swift-BAT further refined analysis
  4. GRB 050315 I-band observations
  5. GRB050315: Radio afterglow
  6. GRB050315: Swift-BAT Refined analysis
  7. GRB 050219b: Gemini/GNIRS near-infrared spectroscopy
  8. Swift-BAT detection of GRB 050315
  9. GRB050309: CONCAM pre-trigger and trigger coincident optical
  10. GRB 050306: optical afterglow
  11. Swift-BAT trigger 107873: No Swift XRT counterpart
  12. GRB 050306: Confirmation of X-ray afterglow
  13. GRB 050309, Early optical limits from RAPTOR
  14. GRB050309: Early optical limit from P60
  15. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  16. GRB 050306: CORRECTION to date of observation
  17. GRB 050306: No Swift UVOT Optical Counterpart Detected
  18. GRB 050306: REM optical-infrared observations
  19. GRB 050306: Possible X-ray Afterglow Position from the Swift
  20. GRB 050306,optical observation
  21. GRB 050306: Swift-BAT detection of a long burst
  22. Ongoing activity of SGR 1806-20 after the giant flare
  23. GRB050215B: Late-Time Swift UVOT Observations
  24. PROMPT VRcIc Observations of GRB 050223
  25. IBAS GRB Alert #2321
  26. INTEGRAL detection of GRB 050223
  27. GRB 050223 Swift/BAT detection of a burst
  28. GRB 050223: Swift XRT Position
  29. GRB050219b: CORRECTION to time of UVOT observations
  30. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  31. GRB 050219b: Swift-BAT detection of a burst
  32. GRB 050219: Swift-BAT detection of a burst
  33. GRB050215b: Swift UVOT Detection of Afterglow Emission
  34. GRB050215b: P60 Optical Observations
  35. GRB 050215b: Swift XRT Observations
  36. Swift-BAT detects two bursts: GRB050215a and GRB050215b
  37. GRB 050215b, BOOTES-1B optical limit
  38. GRB050209: REM optical observations
  39. GRB 050209 Optical observations
  40. GRB050209: P60 Optical Observations
  41. Further analysis of the short Swift-BAT GRB 050202
  42. GRB 050129: Optical observations
  43. GRB 050202: Optical observations with LCO40
  44. GRB 050128 Optical observation with REM
  45. GRB 050129: a weak long GRB detected with INTEGRAL
  46. GRB050128: Faulkes Telescope South observations
  47. GRB050128,optical observations
  48. GRB050126: Updated Swift XRT Position
  49. GRB050126: MASTER optical limit for KECK OT
  50. GRB050126: MASTER optical observations
  51. GRB 050126: Prompt XRT detection and localization
  52. GRB 050124 I-band observation
  53. GRB050124,optical observation
  54. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  55. GRB050123,optical observation
  56. GRB050123: P60 Observations
  57. GRB 050123(=H3666): A GRB Localized in Real Time by HETE
  58. Unusual optical transient (GRB ???)
  59. GRB050117a: Refined analysis
  60. GRB050117: Palomar WIRC Ks-band observations
  61. GRB050117: Refined XRT position
  62. GRB050117: MASTER optical observations
  63. MASTER:GRB050117 SWIFT
  64. GRB050117: Swift-BAT detection of a long multi-peaked burst
  65. Triangulation of Short Hard GRB050112 (large error box)
  66. SGR1806: Optical Transient Candidates in SOHO/LASCO Images
  67. Further ATCA observations of SGR 1806-20
  68. SGR 1806-20: Low frequency GMRT results; submission to GCN circulars
  69. SGR 1806-20, RHESSI observations of the 041227 giant flare
  70. Third epoch observations of SGR 1806-20 with VLA
  71. Second-epoch VLA observations of SGR 1806-20
  72. SGR1806 VLA Observations
  73. GRB041219, early time observations
  74. Detection of the SGR 1806-20 giant outburst back-scattered by the
  75. The giant outburst from SGR 1806-20
  76. IPN localization of giant flare from SGR1806-20
  77. Giant flare from SGR 1806-20 detected by INTEGRAL
  78. GRB041219; RXTE ASM Observations
  79. Swift-BAT Time History of GRB041219
  80. GRB 041219c: PROMPT Observations
  81. GRB 041218: optical observations
  82. Very high activity of SGR 1806-20
  83. GRB 041219 : optical follow-up observations
  84. GRB 041218 Optical Observations
  85. GRB 041219 Optical Observations
  86. GRB041219: Continued NIR Observations
  87. GRB 041219 ,optical observation
  88. GRB 041218: R-band optical observations
  89. GRB041218: Liverpool Telescope optical observations
  90. GRB041218: Continued P60 Optical Observations
  91. GRB 041219: Infrared Afterglow Candidate
  92. GRB 041219: Infrared Afterglow Candidate
  93. GRB 041219 - A long GRB detected by INTEGRAL
  94. GRB 041217: PROMPT Observations
  95. GRB 041218 - A long GRB detected by integral
  96. GRB041217: Infrared Observations
  97. GRB041217: The First GRB Located On-Board Swift
  98. GRB041211: Faulkes Telescope continued optical monitoring
  99. GRB041211: Continued P60 Observations
  100. GRB041211: Ashra Prototype optical observation

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