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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"

21770 results found.

  1. Swift-BAT detection of GRB 050406
  2. Konus-Wind observation of GRB 050401
  3. GRB050401, radio observation at 4.8 GHz and 8.64 GHz
  4. GRB 050401 BAT refined analysis
  5. GRB050401: TNG R-band observation
  6. GRB 050402: Early observations with Swift-UVOT
  7. Swift Trigger 113225: P60 Observations
  8. GRB050401: ROTSE-III Detection of Prompt Optical Counterpart
  9. GRB 050401: Optical afterglow confirmed
  10. Swift-BAT detection of GRB 050401
  11. GRB050331: No Afterglow Detected
  12. GRB 050331: Swift UVOT Source
  13. Swift Data Publicly Available Starting April 5, 2005
  14. Konus-Wind observation of GRB 050326
  15. GRB 050326: Early observations with Swift-UVOT
  16. GRB 050326 XMM-Newton observation
  17. GRB 050326: Swift XRT Position
  18. GRB 050326 BAT refined analysis
  19. GRB050326: delayed XRT observation
  20. Swift-BAT detection of a bright GRB 050326
  21. GRB050319: optical observation, March 20-22
  22. GRB050319: RTT150 Optical Observations
  23. GRB 050319: ROTSE-III Refined Analysis
  24. GRB050319: VLA Observations
  25. GRB050319: radio observation
  26. GRB 050319: Swift-UVOT detection of the afterglow
  27. GRB050319: Radio Observations
  28. GRB 050319: NIR afterglow candidate
  29. GRB 050319:Near IR afterglow
  30. GRB050319,optical observation
  31. GRB 050318: Swift/UVOT detection of afterglow emission
  32. RXTE Observations of GRB050318
  33. GRB050223: analysis of the XMM-Newton observation
  34. GRB050316: MASTER before, simultanious and follow up optical
  35. GRB 050306: ROTSE-III early limits
  36. GRB050316: MASTER optical observations
  37. GRB 050315: Swift-BAT further refined analysis
  38. GRB 050315 I-band observations
  39. GRB050315: Radio afterglow
  40. GRB 050219b: Gemini/GNIRS near-infrared spectroscopy
  41. GRB 050315: Early Observations with Swift/UVOT
  42. GRB050223: No XMM-Newton OM detection of afterglow emission
  43. GRB 050306: Radio Observations
  44. GRB 050306: optical afterglow
  45. Swift-BAT trigger 107873: No Swift XRT counterpart
  46. GRB 050306: Confirmation of X-ray afterglow
  47. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  48. Swift 107873: P60 Optical Observations
  49. GRB 050306: CORRECTION to date of observation
  50. GRB 050306: R-band observations
  51. GRB 050306: No Swift UVOT Optical Counterpart Detected
  52. GRB 050306: REM optical-infrared observations
  53. GRB 050306: Possible X-ray Afterglow Position from the Swift
  54. Swift trigger 107518: optical observation
  55. GRB 050306: TAROT optical observations
  56. GRB 050306,optical observation
  57. GRB050215B: Late-Time Swift UVOT Observations
  58. PROMPT VRcIc Observations of GRB 050223
  59. XMM-Newton Images of GRB 050223
  60. GRB 050219b: candidate NIR afterglow
  61. GRB 050223: optical observations
  62. GRB050223 XMM-Newton observation
  63. GRB050223: ROTSE-III Optical Observations
  64. GRB 050223: Swift XRT Position
  65. HETE-2 Observations of GRB 050215b (=U11570): A Likely X-Ray Flash
  66. GRB050215b: Faulkes North and SDSS limits on UKIRT candidate
  67. GRB 050219a: Optical observations from LCO
  68. GRB 050219b: Optical and near-IR observations from LCO
  69. GRB 050219b: Swift-BAT detection of a burst
  70. GRB 050219a, optical observations
  71. GRB 050215b: XRT confirmation of IR afterglow candidate
  72. GRB050215b: P60 Optical Observations
  73. GRB 050215b: Swift XRT Source Variability
  74. GRB 050215b, BOOTES-2 simultaneous optical observations
  75. GRB 050215B: UKIRT K-band imaging
  76. GRB050215B: ROTSE-III optical observations
  77. GRB050215A: ROTSE-III Optical Observations
  78. GRB050209: TAROT optical observations
  79. GRB050209: REM optical observations
  80. GRB 050209 I-band observation
  81. GRB 050209 Optical observations
  82. GRB050209: P60 Optical Observations
  83. GRB 050209: Optical observation
  84. GRB 050128: Radio observations
  85. GRB050202: Radio Observations
  86. GRB 050202: Short burst detected by Swift-BAT
  87. GRB 050128 Optical observation with REM
  88. SGR1806-20: Swift-BAT detection of a large normal burst
  89. GRB 050128: near-infrared observations with REM
  90. GRB050128,optical observations
  91. GRB050126: Updated Swift XRT Position
  92. GRB 050126: Radio Observations
  93. GRB 050128: Swift XRT prompt afterglow position
  94. GRB050126: MASTER optical limit for KECK OT
  95. GRB050126: MASTER optical observations
  96. GRB 050126: Detection of NIR afterglow with Keck/NIRC
  97. GRB 050124 I-band observation
  98. GRB050124,optical observation
  99. GRB050124: Updated Swift XRT Position and Fluxes
  100. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission

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