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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"

32487 results found.

  1. GRB050713: Liverpool Telescope prompt observations
  2. GRB 050712, optical observations
  3. GRB050709: Candidate X-ray Afterglow from Chandra
  4. GRB 050713: ARC NIR Detections and Identification of Fading
  5. GRB050713: possible I-band afterglow
  6. GRB 050713A: ROTSE-III Optical Limits
  7. GRB050712: XRT refined analysis
  8. GRB050709: Radio Observations
  9. GRB 050709: Swift UVOT and XRT observations
  10. GRB 050712: Swift-BAT Refined Analysis
  11. GRB050712: UVOT candidate optical counterpart
  12. GRB 050712: Swift XRT afterglow position
  13. GRB 050709: LCO40 Observations
  14. GRB050709, optical observations
  15. GRB050709: A Possible Short-Hard GRB Localized by HETE
  16. GRB 050525a: PROMPT VRcIc Detections
  17. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  18. GRB 050626 optical observations
  19. GRB 050701
  20. GRB 050701, optical observations
  21. GRB 050408: ARC 3.5-meter NIR Observations
  22. GRB 050701: Refined XRT analysis
  23. Swift UVOT observations of GRB 050701
  24. GRB050701: Swift-BAT Refined analysis
  25. GRB 050701: Swift XRT afterglow position
  26. GRB 050607, radio observations
  27. H11603: An X-ray flare from V4641 Sgr, or a possible XRF
  28. GRB 050626 - Correction to GCN 3552
  29. GRB 050626 - a long GRB detected with INTEGRAL
  30. GRB 050525A: Swift Late-Time Decay Rate
  31. GRB050525a: HST Observations
  32. CORRECTION: GRB050603 Swift UVOT Afterglow Observations
  33. H3800 and H3801 on 2005 June 11: two bursts from SGR1806-20 localized by HETE
  34. XRF 050509c: Optical monitoring
  35. XRF050509c: Radio Detection
  36. GRB 050416(a): Host Galaxy Redshift Determination
  37. GRB 050607: MDM Observation
  38. GRB 050607: RTT150 optical observations
  39. GRB050607: refined analysis of prompt REM observations
  40. Swift/UVOT observations of GRB050607
  41. GRB 050607 : Lulin R-band observation
  42. GRB 050607: PROMPT VRcIc Observations
  43. GRB 050607: RAPTOR-S Early Optical Limits
  44. GRB050607: KAIT optical limits
  45. GRB 050525a, Mid-Infrared Observations
  46. GRB 050607: MDM Observations
  47. GRB050607,optical observation
  48. GRB 050607 - XRT refined data analysis
  49. GRB 050603: prediction of t_break
  50. Limits on a SN in the field of GRB 050509b
  51. GRB 050603: Redshift
  52. GRB 050603 - XRT data analysis of the first day
  53. Konus-Wind observation of GRB 050603
  54. GRB 050603: Analysis of UVOT data
  55. GRB050603: Fading Afterglow observed by Swift UVOT
  56. GRB050603, submillimetre observations
  57. GRB 050603: Swift XRT Position
  58. GRB050603: Radio Detection
  59. GRB 050603: Swift-BAT refined analysis of a long three-spiked burst
  60. GRB 050603: Afterglow Identification from LCO
  61. GRB 050603: INTEGRAL shows it is not a short GRB
  62. GRB 050408: jet break in the XRT light curve
  63. GRB 050525a, infrared observations
  64. GRB 050525a, SMARTS optical/IR afterglow observations
  65. Correction to GCN Circ 3502 on GRB 050528
  66. Swift-BAT GRB 050528: a soft burst
  67. Update on Swift-BAT GRB 050528 (Trigger 130679)
  68. GRB050528: BOOTES optical candidate (retraction)
  69. GRB050504: Ashra-P2/3 monitor and Ashra-AFT response
  70. GRB050525a: Radio Observations
  71. GRB 050509b: refined XRT/Chandra afterglow position analysis
  72. GRB050525a: optical upper limits
  73. GRB 050525a: SARA Observations
  74. GRB 050525B: Swift-BAT observations
  75. GRB 050525: MITSuME Optical Observation in VRI
  76. GRB 050525a: MDM Observations
  77. GRB050525A,optical observation
  78. GRB 050525 : Lulin optical afterglow observations
  79. GRB050525: Super-LOTIS observations
  80. GRB 050525, spectral lag pseudo-redshift
  81. GRB 050525a: Gemini/GMOS Spectra
  82. GRB050306: optical afterglow not confirmed
  83. GRB 050525: BART optical observation
  84. GRB 050525A: BOOTES simultaneous optical observations
  85. GRB 050525A: Swift-BAT refined analysis
  86. GRB050525: Optical observations
  87. GRB 050525B: INTEGRAL shows it is unrelated to GRB050525A
  88. Swift/UVOT UV and optical detections of GRB 050525
  89. Konus-Wind observation of GRB 050525
  90. GRB 050525: TAROT observations of the early afterglow
  91. INTEGRAL detection of GRB 050525
  92. GRB 050525, infrared observations
  93. GRB 050525: Optical observation
  94. GRB 050525: observatons of the optical afterglow
  95. GRB050525: ROTSE-III Refined Analysis
  96. GRB 050525 - Very Bright, Not Short
  97. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  98. GRB 050525A: ROTSE-III Detection of Possible Counterpart
  99. XRF050522: NIR observations of XRT candidate
  100. XRF 050522: Swift XRT refined analysis

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