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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"

19386 results found.

  1. GRB 050408: Swift XRT analysis
  2. GRB050408: REM NIR and Optical observation
  3. GRB 050408,optical observation
  4. GRB 050408: Mercator Optical Observations
  5. GRB 050408: Optical afterglow confirmed
  6. GRB 050408: opitcal observation
  7. GRB 050408, optical observations
  8. GRB 050408: Swift XRT Position
  9. GRB 050408: ROTSE-III Optical Limits
  10. GRB050408: MASTER optical observations
  11. GRB050401: Radio Detection
  12. GRB 050406: Magellan optical observations
  13. GRB 050406: early Swift XRT analysis results
  14. GRB 050406 BAT refined analysis
  15. GRB 050406: Early observations with Swift-UVOT
  16. GRB 050406: Swift XRT Position
  17. Swift-BAT detection of GRB 050406
  18. Konus-Wind observation of GRB 050401
  19. GRB050401, radio observation at 4.8 GHz and 8.64 GHz
  20. GRB 050401 BAT refined analysis
  21. GRB050401: TNG R-band observation
  22. GRB 050402: Early observations with Swift-UVOT
  23. Swift Trigger 113225: P60 Observations
  24. GRB050401: ROTSE-III Detection of Prompt Optical Counterpart
  25. GRB 050401: Optical afterglow confirmed
  26. Swift-BAT detection of GRB 050401
  27. GRB050331: No Afterglow Detected
  28. GRB 050331: Swift UVOT Source
  29. Swift Data Publicly Available Starting April 5, 2005
  30. Konus-Wind observation of GRB 050326
  31. GRB 050326: Early observations with Swift-UVOT
  32. GRB 050326 XMM-Newton observation
  33. GRB 050326: Swift XRT Position
  34. GRB 050326 BAT refined analysis
  35. GRB050326: delayed XRT observation
  36. Swift-BAT detection of a bright GRB 050326
  37. GRB050319: optical observation, March 20-22
  38. GRB050319: RTT150 Optical Observations
  39. GRB 050319: ROTSE-III Refined Analysis
  40. GRB050319: VLA Observations
  41. GRB050319: radio observation
  42. GRB 050319: Swift-UVOT detection of the afterglow
  43. GRB050319: Radio Observations
  44. GRB 050319: NIR afterglow candidate
  45. GRB 050319:Near IR afterglow
  46. GRB050319,optical observation
  47. GRB 050318: Swift/UVOT detection of afterglow emission
  48. RXTE Observations of GRB050318
  49. GRB050223: analysis of the XMM-Newton observation
  50. GRB050316: MASTER before, simultanious and follow up optical
  51. GRB 050306: ROTSE-III early limits
  52. GRB050316: MASTER optical observations
  53. GRB 050315: Swift-BAT further refined analysis
  54. GRB 050315 I-band observations
  55. GRB050315: Radio afterglow
  56. GRB 050219b: Gemini/GNIRS near-infrared spectroscopy
  57. GRB 050315: Early Observations with Swift/UVOT
  58. GRB050223: No XMM-Newton OM detection of afterglow emission
  59. GRB 050306: Radio Observations
  60. GRB 050306: optical afterglow
  61. Swift-BAT trigger 107873: No Swift XRT counterpart
  62. GRB 050306: Confirmation of X-ray afterglow
  63. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  64. Swift 107873: P60 Optical Observations
  65. GRB 050306: CORRECTION to date of observation
  66. GRB 050306: R-band observations
  67. GRB 050306: No Swift UVOT Optical Counterpart Detected
  68. GRB 050306: REM optical-infrared observations
  69. GRB 050306: Possible X-ray Afterglow Position from the Swift
  70. Swift trigger 107518: optical observation
  71. GRB 050306: TAROT optical observations
  72. GRB 050306,optical observation
  73. GRB050215B: Late-Time Swift UVOT Observations
  74. PROMPT VRcIc Observations of GRB 050223
  75. XMM-Newton Images of GRB 050223
  76. GRB 050219b: candidate NIR afterglow
  77. GRB 050223: optical observations
  78. GRB050223 XMM-Newton observation
  79. GRB050223: ROTSE-III Optical Observations
  80. GRB 050223: Swift XRT Position
  81. HETE-2 Observations of GRB 050215b (=U11570): A Likely X-Ray Flash
  82. GRB050215b: Faulkes North and SDSS limits on UKIRT candidate
  83. GRB 050219a: Optical observations from LCO
  84. GRB 050219b: Optical and near-IR observations from LCO
  85. GRB 050219b: Swift-BAT detection of a burst
  86. GRB 050219a, optical observations
  87. GRB 050215b: XRT confirmation of IR afterglow candidate
  88. GRB050215b: P60 Optical Observations
  89. GRB 050215b: Swift XRT Source Variability
  90. GRB 050215b, BOOTES-2 simultaneous optical observations
  91. GRB 050215B: UKIRT K-band imaging
  92. GRB050215B: ROTSE-III optical observations
  93. GRB050215A: ROTSE-III Optical Observations
  94. GRB050209: TAROT optical observations
  95. GRB050209: REM optical observations
  96. GRB 050209 I-band observation
  97. GRB 050209 Optical observations
  98. GRB050209: P60 Optical Observations
  99. GRB 050209: Optical observation
  100. GRB 050128: Radio observations

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