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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"

15245 results found.

  1. GRB050418: Null Optical Observations
  2. GRB 050416: Mitsume optical observation
  3. GRB 050416: Swift/UVOT detection of afterglow emission
  4. GRB 050416,optical observation
  5. GRB050416: P200 NIR Observations
  6. GRB 050416: Swift XRT Position
  7. GRB 050412: Subaru observations
  8. GRB 050408: Kuiper 1.5m observations
  9. GRB 050408: refined XRT analysis, no jet break seen yet
  10. GRB 050412 : XingLong optical observation
  11. GRB 050412: Swift-BAT refined analysis
  12. GRB 050412: ANU 2.3m observations
  13. GRB 050412: retraction of UVOT transient report
  14. GRB050412: P60 Observations
  15. GRB 050412: Swift XRT Position
  16. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  17. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  18. GRB 050408: PROMPT VRcIc Observations
  19. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  20. GRB 050408: Subaru Observations
  21. GRB 050408: WIDGET simultaneous optical observations
  22. GRB 050408: Properties of the Host Galaxy
  23. GRB 050408: Mercator Optical Observations
  24. GRB 050408, SMARTS optical/IR afterglow observations
  25. GRB 050408: Moderate-resolution Gemini Spectroscopy
  26. GRB 050408,optical observation
  27. GRB 050408: Emission and absorption redshift
  28. GRB 050408: Mercator Optical Observations
  29. GRB 050408: Magellan astrometry and photometry
  30. GRB 050408: steepening of the optical decay
  31. GRB 050408: ROTSE-III Optical Limits
  32. GRB 050408 (=H3711): A Long X-Ray-Rich GRB Detected by HETE
  33. GRB 050406 BAT refined analysis
  34. Konus-Wind observation of GRB 050401
  35. GRB 050401: VLT spectroscopic redshift
  36. GRB 050401 Optical Observations
  37. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
  38. GRB050401: TNG R-band observation
  39. GRB050401: ROTSE-III Detection of Prompt Optical Counterpart
  40. GRB 050401: Prompt XRT position
  41. Retraction of three Swift GRB triggers
  42. GRB050331: No Afterglow Detected
  43. Swift-BAT detection of GRB 050331b
  44. Konus-Wind observation of GRB 050326
  45. GRB050319, optical observations
  46. GRB050319, color indices
  47. Swift-BAT trigger 112060 is not a real GRB
  48. GRB 050319: ROTSE-III Refined Analysis
  49. GRB 050319: Swift-UVOT detection of the afterglow
  50. GRB 050315: Variability Analysis of Swift BAT Time History
  51. GRB050319: BR optical photometry
  52. GRB 050319: Optical observation
  53. GRB050319,optical observation
  54. GRB050318: Swift XRT position
  55. RXTE Observations of GRB050318
  56. GRB 050315, SMARTS optical afterglow decay
  57. GRB050223: analysis of the XMM-Newton observation
  58. GRB 050315: Swift-BAT further refined analysis
  59. GRB 050315, SMARTS optical/IR afterglow observations
  60. GRB050315: Radio afterglow
  61. GRB 050315: Absorption redshift
  62. GRB 050315: Swift XRT Position
  63. GRB 050219b: Gemini/GNIRS near-infrared spectroscopy
  64. GRB050306: 250 GHz upper limit with MAMBO at the IRAM 30m
  65. GRB 050126: Redshift determination
  66. Swift-BAT trigger 107873: No Swift XRT counterpart
  67. GRB 050306: Confirmation of X-ray afterglow
  68. GRB 050309, Early optical limits from RAPTOR
  69. GRB 050306: CORRECTION to date of observation
  70. GRB 050306: R-band observations
  71. GRB 050306: No Swift UVOT Optical Counterpart Detected
  72. Swift trigger 107518: optical observation
  73. PROMPT VRcIc Observations of GRB 050223
  74. GRB 050219b: candidate NIR afterglow
  75. Confirmed XRF nature for GRB050215b
  76. HETE-2 Observations of GRB 050215b (=U11570): A Likely X-Ray Flash
  77. GRB050215b: Faulkes North and SDSS limits on UKIRT candidate
  78. GRB 050219b: CORRECTION to refined XRT position
  79. GRB 050219b: CORRECTION: Swift XRT Position
  80. GRB 050219b: Swift XRT Position
  81. GRB050215b: Swift UVOT Detection of Afterglow Emission
  82. GRB 050215b: XRT confirmation of IR afterglow candidate
  83. GRB 050215b: Swift XRT Source Variability
  84. GRB 050215B: candidate afterglow
  85. GRB 050215b : Lulin follow-up observation
  86. GRB 050215B: UKIRT K-band imaging
  87. GRB 050209(=U11568): Duration and spectrum
  88. short/hard GRB 050202, optical observations
  89. GRB 050202: Optical observations with LCO40
  90. GRB 050202: Short burst detected by Swift-BAT
  91. GRB 050124: Radio Observations
  92. GRB 050128: Swift XRT prompt afterglow position
  93. GRB 050124 : Lulin R-band follow-up observation
  94. GRB050124: Swift-BAT position of a double-peaked burst
  95. GRB 050123 : I-band follow-up observation
  96. Unusual optical transient (GRB ???)
  97. GRB050117: optical observation
  98. GRB050117: Refined XRT position
  99. GRB050117: Swift XRT Position
  100. SGR 1806-20: RXTE/PCA pulse frequency during flare

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