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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"

21267 results found.

  1. GRB 050401 BAT refined analysis
  2. GRB050401: TNG R-band observation
  3. GRB 050402: Early observations with Swift-UVOT
  4. Swift Trigger 113225: P60 Observations
  5. GRB050401: ROTSE-III Detection of Prompt Optical Counterpart
  6. GRB 050401: Optical afterglow confirmed
  7. Swift-BAT detection of GRB 050401
  8. GRB050331: No Afterglow Detected
  9. GRB 050331: Swift UVOT Source
  10. Swift Data Publicly Available Starting April 5, 2005
  11. Konus-Wind observation of GRB 050326
  12. GRB 050326: Early observations with Swift-UVOT
  13. GRB 050326 XMM-Newton observation
  14. GRB 050326: Swift XRT Position
  15. GRB 050326 BAT refined analysis
  16. GRB050326: delayed XRT observation
  17. Swift-BAT detection of a bright GRB 050326
  18. GRB050319: optical observation, March 20-22
  19. GRB050319: RTT150 Optical Observations
  20. GRB 050319: ROTSE-III Refined Analysis
  21. GRB050319: VLA Observations
  22. GRB050319: radio observation
  23. GRB 050319: Swift-UVOT detection of the afterglow
  24. GRB050319: Radio Observations
  25. GRB 050319: NIR afterglow candidate
  26. GRB 050319:Near IR afterglow
  27. GRB050319,optical observation
  28. GRB 050318: Swift/UVOT detection of afterglow emission
  29. RXTE Observations of GRB050318
  30. GRB050223: analysis of the XMM-Newton observation
  31. GRB050316: MASTER before, simultanious and follow up optical
  32. GRB 050306: ROTSE-III early limits
  33. GRB050316: MASTER optical observations
  34. GRB 050315: Swift-BAT further refined analysis
  35. GRB 050315 I-band observations
  36. GRB050315: Radio afterglow
  37. GRB 050219b: Gemini/GNIRS near-infrared spectroscopy
  38. GRB 050315: Early Observations with Swift/UVOT
  39. GRB050223: No XMM-Newton OM detection of afterglow emission
  40. GRB 050306: Radio Observations
  41. GRB 050306: optical afterglow
  42. Swift-BAT trigger 107873: No Swift XRT counterpart
  43. GRB 050306: Confirmation of X-ray afterglow
  44. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  45. Swift 107873: P60 Optical Observations
  46. GRB 050306: CORRECTION to date of observation
  47. GRB 050306: R-band observations
  48. GRB 050306: No Swift UVOT Optical Counterpart Detected
  49. GRB 050306: REM optical-infrared observations
  50. GRB 050306: Possible X-ray Afterglow Position from the Swift
  51. Swift trigger 107518: optical observation
  52. GRB 050306: TAROT optical observations
  53. GRB 050306,optical observation
  54. GRB050215B: Late-Time Swift UVOT Observations
  55. PROMPT VRcIc Observations of GRB 050223
  56. XMM-Newton Images of GRB 050223
  57. GRB 050219b: candidate NIR afterglow
  58. GRB 050223: optical observations
  59. GRB050223 XMM-Newton observation
  60. GRB050223: ROTSE-III Optical Observations
  61. GRB 050223: Swift XRT Position
  62. HETE-2 Observations of GRB 050215b (=U11570): A Likely X-Ray Flash
  63. GRB050215b: Faulkes North and SDSS limits on UKIRT candidate
  64. GRB 050219a: Optical observations from LCO
  65. GRB 050219b: Optical and near-IR observations from LCO
  66. GRB 050219b: Swift-BAT detection of a burst
  67. GRB 050219a, optical observations
  68. GRB 050215b: XRT confirmation of IR afterglow candidate
  69. GRB050215b: P60 Optical Observations
  70. GRB 050215b: Swift XRT Source Variability
  71. GRB 050215b, BOOTES-2 simultaneous optical observations
  72. GRB 050215B: UKIRT K-band imaging
  73. GRB050215B: ROTSE-III optical observations
  74. GRB050215A: ROTSE-III Optical Observations
  75. GRB050209: TAROT optical observations
  76. GRB050209: REM optical observations
  77. GRB 050209 I-band observation
  78. GRB 050209 Optical observations
  79. GRB050209: P60 Optical Observations
  80. GRB 050209: Optical observation
  81. GRB 050128: Radio observations
  82. GRB050202: Radio Observations
  83. GRB 050202: Short burst detected by Swift-BAT
  84. GRB 050128 Optical observation with REM
  85. SGR1806-20: Swift-BAT detection of a large normal burst
  86. GRB 050128: near-infrared observations with REM
  87. GRB050128,optical observations
  88. GRB050126: Updated Swift XRT Position
  89. GRB 050126: Radio Observations
  90. GRB 050128: Swift XRT prompt afterglow position
  91. GRB050126: MASTER optical limit for KECK OT
  92. GRB050126: MASTER optical observations
  93. GRB 050126: Detection of NIR afterglow with Keck/NIRC
  94. GRB 050124 I-band observation
  95. GRB050124,optical observation
  96. GRB050124: Updated Swift XRT Position and Fluxes
  97. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  98. GRB050123,optical observation
  99. GRB 050123: KAIT observations
  100. GRB050117a: Refined analysis

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