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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"

16168 results found.

  1. GRB 050219b: Gemini/GNIRS near-infrared spectroscopy
  2. GRB 050315: Early Observations with Swift/UVOT
  3. GRB050223: No XMM-Newton OM detection of afterglow emission
  4. GRB 050306: Radio Observations
  5. GRB050306: 250 GHz upper limit with MAMBO at the IRAM 30m
  6. GRB050309: CONCAM pre-trigger and trigger coincident optical
  7. GRB 050306: optical afterglow
  8. GRB 050309, Early optical limits from RAPTOR
  9. GRB 050306: further TAROT optical data
  10. GRB050309: Early optical limit from P60
  11. Swift 107873: P60 Optical Observations
  12. GRB 050306: CORRECTION to date of observation
  13. GRB 050306: No Swift UVOT Optical Counterpart Detected
  14. GRB 050306: REM optical-infrared observations
  15. Swift trigger 107518: optical observation
  16. GRB 050306: TAROT optical observations
  17. GRB 050306,optical observation
  18. GRB050215B: Late-Time Swift UVOT Observations
  19. PROMPT VRcIc Observations of GRB 050223
  20. GRB 050219b: candidate NIR afterglow
  21. GRB 050223: optical observations
  22. GRB050223: No Swift UVOT Detection of Afterglow Emission
  23. GRB050223: ROTSE-III Optical Observations
  24. HETE-2 Observations of GRB 050215b (=U11570): A Likely X-Ray Flash
  25. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  26. GRB 050219a: Optical observations from LCO
  27. GRB 050219b: Optical and near-IR observations from LCO
  28. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  29. GRB 050219a, optical observations
  30. GRB050219a: No Swift UVOT Detection of Afterglow Emission
  31. GRB050215b: Swift UVOT Detection of Afterglow Emission
  32. GRB 050215B: Radio Observations
  33. GRB 050215b: XRT confirmation of IR afterglow candidate
  34. GRB050215b: P60 Optical Observations
  35. GRB 050215b: Swift XRT Source Variability
  36. GRB 050215b, BOOTES-2 simultaneous optical observations
  37. GRB 050215b: Swift XRT Observations
  38. GRB050215b: No Swift UVOT Detection of Afterglow Emission
  39. GRB050215a: No Swift UVOT Detection of Afterglow Emission
  40. Swift-BAT detects two bursts: GRB050215a and GRB050215b
  41. GRB 050215b, BOOTES-1B optical limit
  42. GRB050215B: ROTSE-III optical observations
  43. GRB050215A: ROTSE-III Optical Observations
  44. GRB050209: TAROT optical observations
  45. GRB 050209(=U11568): Duration and spectrum
  46. short/hard GRB 050202, optical observations
  47. GRB050209: REM optical observations
  48. GRB 050209 Optical observations
  49. GRB050209: P60 Optical Observations
  50. GRB050209 (=U11568): A Long GRB Detected by HETE
  51. GRB 050209: Optical observation
  52. Further analysis of the short Swift-BAT GRB 050202
  53. GRB 050129: Optical observations
  54. GRB 050202: Optical observations with LCO40
  55. GRB 050128 Optical observation with REM
  56. GRB 050128: near-infrared observations with REM
  57. GRB050128,optical observations
  58. GRB 050128: Swift XRT prompt afterglow position
  59. GRB050126: MASTER optical limit for KECK OT
  60. GRB050126: MASTER optical observations
  61. GRB050124: No Swift UVOT Detection of Afterglow Emission
  62. GRB 050124, SMARTS optical/IR observations
  63. GRB050124,optical observation
  64. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  65. GRB050123: optical limit 1.8h before GRB
  66. GRB050123,optical observation
  67. GRB 050123(=H3666): A GRB Localized in Real Time by HETE
  68. CFHTLS optical transient unlikely to be a GRB
  69. Unusual optical transient (GRB ???)
  70. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  71. GRB050117: optical observation
  72. GRB 050117: Optical observation
  73. GRB050117: MASTER optical observations
  74. MASTER:GRB050117 SWIFT
  75. SGR1806: Optical Transient Candidates in SOHO/LASCO Images
  76. SGR 1806-20 and extragalactic short-duration GRBs
  77. GRB 041217: Optical observations
  78. GRB041219, early time observations
  79. GRB041228: ROTSE-III Optical Observations
  80. GRB041226: ROTSE-III Optical Observations
  81. GRB041223: decay of the afterglow
  82. GRB041224: ROTSE-III Optical Observations
  83. GRB 041224: near-infrared observations with REM
  84. GRB 041223: XRT afterglow spectrum and light curve
  85. GRB041223: optical and NIR observations with REM
  86. Swift-BAT Time History of GRB041219
  87. GRB 041219: TAROT optical observations
  88. GRB 041218: TAROT optical observations
  89. GRB 041223: Detection of Optical Transient with LCO40
  90. GRB041223: ROTSE-III Optical Observations
  91. GRB 041218: optical observations
  92. GRB 041218: Optical observations
  93. GRB 041219 : optical follow-up observations
  94. Deep RAPTOR observations during GRB 041219
  95. GRB 041218 Optical Observations
  96. GRB 041219 Optical Observations
  97. GRB041219: Optical Afterglow Detection
  98. GRB041219: Continued NIR Observations
  99. GRB 041219 ,optical observation
  100. GRB 041219: Radio Afterglow Detection

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