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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"

27293 results found.

  1. Swift-BAT detection of GRB 050318
  2. GRB 050315, SMARTS optical afterglow decay
  3. GRB050223: analysis of the XMM-Newton observation
  4. GRB 050306: ROTSE-III early limits
  5. GRB 050315: Swift-BAT further refined analysis
  6. GRB 050315, SMARTS optical/IR afterglow observations
  7. GRB050315: Swift-BAT Refined analysis
  8. Non-detection of GRB050315 in ATCA Radio Observations
  9. GRB 050315: Swift XRT Position
  10. GRB 050315: Early Observations with Swift/UVOT
  11. Swift-BAT detection of GRB 050315
  12. GRB050223: No XMM-Newton OM detection of afterglow emission
  13. GRB 050306: Radio Observations
  14. GRB050306: 250 GHz upper limit with MAMBO at the IRAM 30m
  15. GRB050309: CONCAM pre-trigger and trigger coincident optical
  16. GRB 050126: Redshift determination
  17. Swift-BAT trigger 107873: No Swift XRT counterpart
  18. GRB 050306: Confirmation of X-ray afterglow
  19. GRB 050309, Early optical limits from RAPTOR
  20. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  21. GRB 050309 : Lulin R-band observation
  22. Swift 107873: P60 Optical Observations
  23. GRB 050306: CORRECTION to date of observation
  24. GRB 050306: No Swift UVOT Optical Counterpart Detected
  25. GRB 050306: Possible X-ray Afterglow Position from the Swift
  26. Swift trigger 107518: optical observation
  27. GRB 050306,optical observation
  28. GRB 050306: Swift-BAT detection of a long burst
  29. GRB050215B: Late-Time Swift UVOT Observations
  30. PROMPT VRcIc Observations of GRB 050223
  31. GRB 050223: optical observations
  32. GRB050223 XMM-Newton observation
  33. INTEGRAL detection of GRB 050223
  34. GRB050223: No Swift UVOT Detection of Afterglow Emission
  35. GRB050223: ROTSE-III Optical Observations
  36. GRB 050223 Swift/BAT detection of a burst
  37. GRB 050223: Swift XRT Position
  38. GRB050219b: CORRECTION to time of UVOT observations
  39. GRB050215b: Faulkes North and SDSS limits on UKIRT candidate
  40. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  41. GRB 050219b: CORRECTION to refined XRT position
  42. GRB 050219b: Optical and near-IR observations from LCO
  43. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  44. GRB 050219b: Refined XRT position
  45. GRB 050219b: Swift-BAT detection of a burst
  46. GRB 050219b: CORRECTION: Swift XRT Position
  47. GRB 050219b: Swift XRT Position
  48. GRB 050219a, optical observations
  49. GRB 050219a: Refined XRT position
  50. GRB050219a: No Swift UVOT Detection of Afterglow Emission
  51. GRB 050219: Swift-BAT detection of a burst
  52. GRB050215b: Swift UVOT Detection of Afterglow Emission
  53. GRB 050219: Prompt X-ray position
  54. GRB 050215b: XRT confirmation of IR afterglow candidate
  55. GRB050215b: P60 Optical Observations
  56. GRB 050215b: Swift XRT Source Variability
  57. GRB 050215B: candidate afterglow
  58. GRB 050215b : Lulin follow-up observation
  59. GRB 050215b, BOOTES-2 simultaneous optical observations
  60. GRB 050215B: UKIRT K-band imaging
  61. GRB 050215b: Swift XRT Observations
  62. GRB050215b: No Swift UVOT Detection of Afterglow Emission
  63. GRB050215a: No Swift UVOT Detection of Afterglow Emission
  64. Swift-BAT detects two bursts: GRB050215a and GRB050215b
  65. GRB050215B: ROTSE-III optical observations
  66. GRB050215A: ROTSE-III Optical Observations
  67. short/hard GRB 050202, optical observations
  68. GRB 050128: Radio observations
  69. Further analysis of the short Swift-BAT GRB 050202
  70. GRB 050202: Second epoch radio observations
  71. GRB050202: Radio Observations
  72. GRB 050202: Short burst detected by Swift-BAT
  73. SGR1806-20: Swift-BAT detection of a large normal burst
  74. GRB050128: Faulkes Telescope South observations
  75. GRB 050128: near-infrared observations with REM
  76. GRB050128,optical observations
  77. GRB050126: Updated Swift XRT Position
  78. SGR 1806-20: GMRT results at 240 MHz band.
  79. SGR 1806-20: low frequency GMRT results of 2005 Jan 16.
  80. GRB 050126: Radio Observations
  81. GRB050128 Swift-BAT observations
  82. GRB 050128: Swift XRT prompt afterglow position
  83. GRB 050124: K-band afterglow observations
  84. GRB050126: MASTER optical limit for KECK OT
  85. GRB050126: Burst Parameters Measured by BAT
  86. GRB050126: MASTER optical observations
  87. GRB 050126: Detection of NIR afterglow with Keck/NIRC
  88. GRB 050126: Prompt XRT detection and localization
  89. GRB050124: No Swift UVOT Detection of Afterglow Emission
  90. GRB 050124, SMARTS optical/IR observations
  91. GRB 050117a: Radio Observations
  92. GRB050124,optical observation
  93. GRB050124: Updated Swift XRT Position and Fluxes
  94. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  95. GRB050124: Refined BAT position, spectral and fluence information
  96. GRB050124: Swift-BAT position of a double-peaked burst
  97. CFHTLS optical transient unlikely to be a GRB
  98. GRB050117a: Radio Observations
  99. GRB050117a: Refined analysis
  100. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations

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