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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"

34313 results found.

  1. Swift-BAT detection of GRB 050331b
  2. GRB 050331: Swift UVOT Source
  3. Swift-BAT detection of GRB 050331
  4. GRB 050331: Swift XRT Position
  5. GRB050319: radio observation
  6. Konus-Wind observation of GRB 050326
  7. GRB 050326: Early observations with Swift-UVOT
  8. GRB 050326 XMM-Newton observation
  9. GRB 050326 : Planned XMM-Newton observation
  10. GRB 050326: Swift XRT Position
  11. GRB050326: optical limit 33min before GRB
  12. GRB 050326 BAT refined analysis
  13. GRB050326: delayed XRT observation
  14. Swift-BAT detection of a bright GRB 050326
  15. GRB050319, color indices
  16. GRB050319: RTT150 Optical Observations
  17. Swift-BAT trigger 112060 is not a real GRB
  18. GRB 050319: Absorption redshift from the Nordic Optical Telescope
  19. GRB 050319: ROTSE-III Refined Analysis
  20. GRB 050318: Swift-BAT refined analysis
  21. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  22. GRB050319: VLA Observations
  23. GRB 050319 R band observations
  24. GRB 050319: Swift-UVOT detection of the afterglow
  25. GRB 050315: Variability Analysis of Swift BAT Time History
  26. GRB050319: Radio Observations
  27. GRB 050319: NIR afterglow candidate
  28. GRB 050319:Near IR afterglow
  29. GRB 050318: SWIFT-UVOT refined analysis
  30. GRB 050318: Absorption redshift from Magellan
  31. GRB 050319: Optical observation
  32. GRB 050319 : Confirmation of optical afterglow decay
  33. GRB 050319: Swift-BAT refined analysis
  34. GRB050319,optical observation
  35. Swift Detection of GRB 050319
  36. GRB 050319: Detection of Possible Optical Counterpart
  37. GRB 050318: Swift/UVOT detection of afterglow emission
  38. GRB 050318: Magellan optical afterglow identification
  39. GRB050318: Swift XRT position
  40. RXTE Observations of GRB050318
  41. Swift-BAT detection of GRB 050318
  42. GRB 050315, SMARTS optical afterglow decay
  43. GRB050316: MASTER before, simultanious and follow up optical
  44. GRB 050306: ROTSE-III early limits
  45. GRB050316: MASTER optical observations
  46. GRB 050315: Swift-BAT further refined analysis
  47. GRB 050315, SMARTS optical/IR afterglow observations
  48. GRB 050315 I-band observations
  49. GRB050315: Radio afterglow
  50. GRB 050315: Absorption redshift
  51. GRB 050315: Optical afterglow identification
  52. GRB050315: Swift-BAT Refined analysis
  53. Non-detection of GRB050315 in ATCA Radio Observations
  54. GRB 050315: Swift XRT Position
  55. GRB 050219b: Gemini/GNIRS near-infrared spectroscopy
  56. GRB 050315: Early Observations with Swift/UVOT
  57. Swift-BAT detection of GRB 050315
  58. GRB 050306: Radio Observations
  59. GRB050306: 250 GHz upper limit with MAMBO at the IRAM 30m
  60. GRB050309: CONCAM pre-trigger and trigger coincident optical
  61. GRB 050306: optical afterglow
  62. GRB 050126: Redshift determination
  63. Swift-BAT trigger 107873: No Swift XRT counterpart
  64. GRB 050306: Confirmation of X-ray afterglow
  65. GRB 050309, Early optical limits from RAPTOR
  66. GRB 050306: further TAROT optical data
  67. GRB050309: Early optical limit from P60
  68. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  69. GRB 050309 : Lulin R-band observation
  70. Swift 107873: P60 Optical Observations
  71. GRB 050306: CORRECTION to date of observation
  72. GRB 050306: R-band observations
  73. GRB 050306: No Swift UVOT Optical Counterpart Detected
  74. GRB 050306: REM optical-infrared observations
  75. GRB 050306: Possible X-ray Afterglow Position from the Swift
  76. Swift trigger 107518: optical observation
  77. GRB 050306: TAROT optical observations
  78. GRB 050306,optical observation
  79. GRB 050306: Swift-BAT detection of a long burst
  80. GRB 050126: Confirmation of the NIR afterglow candidate
  81. PROMPT VRcIc Observations of GRB 050223
  82. XRF/GRB 050215B: Radio Observations
  83. XMM-Newton Images of GRB 050223
  84. GRB 050219b: candidate NIR afterglow
  85. IBAS GRB Alert #2321
  86. GRB 050223: optical observations
  87. INTEGRAL detection of GRB 050223
  88. GRB 050223 : Planned XMM-Newton observation
  89. GRB050223: ROTSE-III Optical Observations
  90. GRB 050223 Swift/BAT detection of a burst
  91. GRB 050223: Swift XRT Position
  92. HETE-2 Observations of GRB 050215b (=U11570): A Likely X-Ray Flash
  93. GRB 050219b: CORRECTION to refined XRT position
  94. GRB 050219a: Optical observations from LCO
  95. GRB 050219b: Optical and near-IR observations from LCO
  96. GRB 050219b: Refined XRT position
  97. GRB 050219b: Swift-BAT detection of a burst
  98. GRB 050219b: CORRECTION: Swift XRT Position
  99. GRB 050219b: Swift XRT Position
  100. GRB 050219a, optical observations

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