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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"

32502 results found.

  1. GRB 091127: Skynet/PROMPT Observations of Fading
  2. GRB 091130B: MASTER observations
  3. GRB 091130B: SDSS galaxy at XRT location
  4. GRB 091130: MASTER observations
  5. GRB 091127: Radio observations
  6. Konus-Wind observation of GRB 091127
  7. GRB 091127: optical observations
  8. GRB 091127: LABOCA/APEX submm observations
  9. GRB 091127: Further NOT optical observations
  10. GRB 091127: Fermi GBM detection
  11. GRB 091127: MASTER early optical transient polarimetry
  12. GRB 091127: Gemini-N redshift
  13. GRB 091127: Swift-XRT afterglow detection and analysis
  14. GRB 091127: Swift/UVOT observations
  15. GRB 091127: CAHA 1.23m I-band observations
  16. GRB 091127: Swift-BAT refined analysis
  17. GRB 091127: NOT observations
  18. GRB 091127 : GROND observations
  19. GRB 091127: REM NIR afterglow detection
  20. GRB 091127: Swift/UVOT Detection of an Optical Afterglow
  21. GRB 091127: Liverpool Telescope afterglow candidate
  22. IPN Triangulation of GRB091120
  23. Konus-Wind observation of GRB 091120
  24. GRB 091117A: Suzaku WAM observation of the prompt emission
  25. GRB 091117: TNG optical observations
  26. GRB 091117A: Swift/UVOT followup observations
  27. GRB 091117: 2nd epoch of Magellan optical observations
  28. GRB 091117: VLA radio observations
  29. GRB 091117: Swift-XRT observations
  30. GRB 091117 BAT refined analysis
  31. GRB 091117: Evidence for Variability of XRT Source #1
  32. GRB091117: Gemini South Observations
  33. GRB 091117: Swift XRT refined analysis
  34. GRB 091117: Gemini-North spectroscopy of DSS galaxy
  35. Konus-Wind observations of GRB 091117A
  36. GRB 091117: Magellan optical observations
  37. GRB 091117: XRT source coincident with a DSS galaxy
  38. GRB 091112: Suzaku WAM observation of the prompt emission
  39. GRB 091102A: Suzaku WAM observation of the prompt emission
  40. GRB 091109B: Suzaku WAM observation of the prompt emission
  41. GRB091111: Swift XRT refined analysis
  42. Konus-Wind and Konus-RF observations of GRB 091031
  43. GRB 091112: Swift-BAT refined analysis
  44. GRB 091112: Fermi GBM observation
  45. GRB 091031: Fermi LAT detection of a faint burst
  46. GRB 091111: BOOTES-3 contemporaneous imaging
  47. GRB 091111: a faint long GRB detected with INTEGRAL
  48. GRB 091109A: GROND and VLT observations
  49. GRB 091109B: Swift/UVOT Upper Limits
  50. GRB 091109B: VLT afterglow confirmation
  51. GRB 091109B: Swift-XRT Team refined analysis
  52. GRB 091109b: Magellan Observations
  53. GRB 091109B: Swift-BAT refined analysis
  54. GRB 091109B: Optical limits from Watcher
  55. GRB 091109B: ROTSE-III Optical Limits
  56. GRB091109: Correction to GCN 10139
  57. GRB 091109: Swift-XRT refined analysis
  58. GRB 091109: BOOTES-3 observations
  59. GRB 091109: Swift/UVOT observations
  60. GRB 091109: Faulkes Telescope South observations
  61. GRB 091109: Swift-BAT refined analysis
  62. GRB 091029: Observations from Stardome Observatory
  63. GRB 091104: Swift-BAT refined analysis
  64. GRB 091104: Swift XRT Refined Analysis
  65. GRB 091104: Swift/UVOT Upper Limits
  66. GRB091026 : IRSF NIR upper limit
  67. GRB091102 : MOA optical upper limit
  68. GRB 091102: LABOCA/APEX submm observations
  69. Fermi LAT Upper Limits on GRB 091010
  70. GRB 091102 : Faulkes Telescope South Upper Limits
  71. GRB 091102A: Fermi GBM observation
  72. GRB 091102: Swift-XRT refined analysis
  73. GRB 091102: Swift/UVOT Upper Limits
  74. GRB 091102: GROND Upper Limits
  75. GRB 091102: BOOTES-3 observations
  76. GRB 091102: Swift-BAT refined analysis
  77. GRB 091102: Swift/XRT localization
  78. GRB 091102: ROTSE-III Optical Limits
  79. GRB 091102: Swift/UVOT Finding Chart Observation
  80. GRB 091024: optical observations
  81. GRB 091031: Fermi GBM detection
  82. GRB 091024: Fermi LAT upper limits
  83. GRB 090926a, SMARTS optical/IR afterglow observations
  84. GRB 091018: Skynet/PROMPT Observations of Possible Host Galaxy
  85. GRB 091029, SMARTS optical/IR afterglow observations
  86. GRB 091018, SMARTS optical/IR afterglow observations
  87. GRB 090920: Skynet/DSO Detection
  88. GRB091029: Swift/UVOT observations
  89. GRB 091029: Skynet/PROMPT Continued Observations of Fading
  90. GRB 091029: Swift XRT refined analysis
  91. GRB 091029: BOOTES-3 observations
  92. GRB 091029: Swift-BAT refined analysis
  93. GRB091024 optical observations
  94. GRB 091029: Gemini-South Redshift
  95. GRB 091029: Skynet/PROMPT Observations of Peak and Fading
  96. GRB 091029: GROND Detection of the Optical/NIR Afterglow
  97. A mistake in testing a new function in Swift
  98. GRB 091020: Fermi GBM observation
  99. GRB 091026: Suzaku WAM observation of the prompt emission
  100. GRB 091024: Keck/LRIS Spectroscopy

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