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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"
  1. GRB 050318: Swift-BAT refined analysis
  2. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  3. GRB050319: VLA Observations
  4. GRB050319: radio observation
  5. GRB 050319 R band observations
  6. GRB 050319: Swift-UVOT detection of the afterglow
  7. GRB 050315: Variability Analysis of Swift BAT Time History
  8. GRB050319: Radio Observations
  9. GRB 050319: NIR afterglow candidate
  10. GRB 050319:Near IR afterglow
  11. GRB050319: BR optical photometry
  12. GRB 050318: SWIFT-UVOT refined analysis
  13. GRB 050318: Absorption redshift from Magellan
  14. GRB 050319: Optical observation
  15. GRB 050319 : Confirmation of optical afterglow decay
  16. GRB 050319: Swift-BAT refined analysis
  17. GRB050319,optical observation
  18. Swift Detection of GRB 050319
  19. GRB 050319: Detection of Possible Optical Counterpart
  20. GRB 050318: Swift/UVOT detection of afterglow emission
  21. GRB 050318: Magellan optical afterglow identification
  22. GRB050318: Swift XRT position
  23. RXTE Observations of GRB050318
  24. Swift-BAT detection of GRB 050318
  25. GRB 050315, SMARTS optical afterglow decay
  26. GRB050223: analysis of the XMM-Newton observation
  27. GRB050316: MASTER before, simultanious and follow up optical
  28. GRB 050306: ROTSE-III early limits
  29. GRB050316: MASTER optical observations
  30. GRB 050315: Swift-BAT further refined analysis
  31. GRB 050315, SMARTS optical/IR afterglow observations
  32. GRB 050315 I-band observations
  33. GRB050315: Radio afterglow
  34. GRB 050315: Absorption redshift
  35. GRB 050315: Optical afterglow identification
  36. GRB050315: Swift-BAT Refined analysis
  37. Non-detection of GRB050315 in ATCA Radio Observations
  38. GRB 050315: Swift XRT Position
  39. GRB 050219b: Gemini/GNIRS near-infrared spectroscopy
  40. GRB 050315: Early Observations with Swift/UVOT
  41. Swift-BAT detection of GRB 050315
  42. GRB050223: No XMM-Newton OM detection of afterglow emission
  43. GRB 050306: Radio Observations
  44. GRB050306: 250 GHz upper limit with MAMBO at the IRAM 30m
  45. GRB050309: CONCAM pre-trigger and trigger coincident optical
  46. GRB 050306: optical afterglow
  47. GRB 050126: Redshift determination
  48. Swift-BAT trigger 107873: No Swift XRT counterpart
  49. GRB 050306: Confirmation of X-ray afterglow
  50. GRB 050309, Early optical limits from RAPTOR
  51. GRB 050306: further TAROT optical data
  52. GRB050309: Early optical limit from P60
  53. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  54. GRB 050309 : Lulin R-band observation
  55. Swift 107873: P60 Optical Observations
  56. GRB 050306: CORRECTION to date of observation
  57. GRB 050306: R-band observations
  58. GRB 050306: No Swift UVOT Optical Counterpart Detected
  59. GRB 050306: REM optical-infrared observations
  60. GRB 050306: Possible X-ray Afterglow Position from the Swift
  61. Swift trigger 107518: optical observation
  62. GRB 050306: TAROT optical observations
  63. GRB 050306,optical observation
  64. GRB 050306: Swift-BAT detection of a long burst
  65. Ongoing activity of SGR 1806-20 after the giant flare
  66. GRB050215B: Late-Time Swift UVOT Observations
  67. GRB 050126: Confirmation of the NIR afterglow candidate
  68. PROMPT VRcIc Observations of GRB 050223
  69. XRF/GRB 050215B: Radio Observations
  70. XMM-Newton Images of GRB 050223
  71. GRB 050219b: candidate NIR afterglow
  72. IBAS GRB Alert #2321
  73. Confirmed XRF nature for GRB050215b
  74. GRB 050223: optical observations
  75. GRB050223 XMM-Newton observation
  76. INTEGRAL detection of GRB 050223
  77. GRB 050223 : Planned XMM-Newton observation
  78. GRB050223: No Swift UVOT Detection of Afterglow Emission
  79. GRB050223: ROTSE-III Optical Observations
  80. GRB 050223 Swift/BAT detection of a burst
  81. GRB 050223: Swift XRT Position
  82. HETE-2 Observations of GRB 050215b (=U11570): A Likely X-Ray Flash
  83. GRB050219b: CORRECTION to time of UVOT observations
  84. GRB050215b: Faulkes North and SDSS limits on UKIRT candidate
  85. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  86. GRB 050219b: CORRECTION to refined XRT position
  87. GRB 050219a: Optical observations from LCO
  88. GRB 050219b: Optical and near-IR observations from LCO
  89. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  90. GRB 050219b: Refined XRT position
  91. GRB 050219b: Swift-BAT detection of a burst
  92. GRB 050219b: CORRECTION: Swift XRT Position
  93. GRB 050219b: Swift XRT Position
  94. GRB 050219a, optical observations
  95. GRB 050219a: Refined XRT position
  96. GRB050219a: No Swift UVOT Detection of Afterglow Emission
  97. GRB 050219: Swift-BAT detection of a burst
  98. GRB050215b: Swift UVOT Detection of Afterglow Emission
  99. GRB 050219: Prompt X-ray position
  100. GRB 050215B: Radio Observations

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