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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"

24934 results found.

  1. GRB 050315: Early Observations with Swift/UVOT
  2. GRB 050306: Radio Observations
  3. GRB050306: 250 GHz upper limit with MAMBO at the IRAM 30m
  4. GRB 050306: optical afterglow
  5. Swift-BAT trigger 107873: No Swift XRT counterpart
  6. GRB 050306: Confirmation of X-ray afterglow
  7. GRB 050306: further TAROT optical data
  8. GRB050309: Early optical limit from P60
  9. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  10. GRB 050309 : Lulin R-band observation
  11. Swift 107873: P60 Optical Observations
  12. GRB 050306: R-band observations
  13. GRB 050306: REM optical-infrared observations
  14. GRB 050306: Possible X-ray Afterglow Position from the Swift
  15. GRB 050306: TAROT optical observations
  16. GRB 050306,optical observation
  17. Ongoing activity of SGR 1806-20 after the giant flare
  18. GRB050215B: Late-Time Swift UVOT Observations
  19. PROMPT VRcIc Observations of GRB 050223
  20. XRF/GRB 050215B: Radio Observations
  21. XMM-Newton Images of GRB 050223
  22. GRB 050219b: candidate NIR afterglow
  23. Confirmed XRF nature for GRB050215b
  24. GRB050223 XMM-Newton observation
  25. INTEGRAL detection of GRB 050223
  26. GRB050223: ROTSE-III Optical Observations
  27. GRB 050223 Swift/BAT detection of a burst
  28. GRB 050223: Swift XRT Position
  29. HETE-2 Observations of GRB 050215b (=U11570): A Likely X-Ray Flash
  30. GRB050215b: Faulkes North and SDSS limits on UKIRT candidate
  31. GRB 050219a: Optical observations from LCO
  32. GRB 050219b: Optical and near-IR observations from LCO
  33. GRB 050219b: Swift-BAT detection of a burst
  34. GRB 050219b: CORRECTION: Swift XRT Position
  35. GRB 050219b: Swift XRT Position
  36. GRB 050219: Swift-BAT detection of a burst
  37. GRB 050215b: XRT confirmation of IR afterglow candidate
  38. GRB050215b: P60 Optical Observations
  39. GRB 050215b: Swift XRT Source Variability
  40. GRB 050215B: candidate afterglow
  41. GRB 050215b : Lulin follow-up observation
  42. GRB 050215b, BOOTES-2 simultaneous optical observations
  43. GRB050215A: ROTSE-III Optical Observations
  44. GRB050209: TAROT optical observations
  45. GRB 050209(=U11568): Duration and spectrum
  46. GRB050209: REM optical observations
  47. GRB 050209 I-band observation
  48. GRB 050209 Optical observations
  49. GRB050209: P60 Optical Observations
  50. GRB 050128: Radio observations
  51. Further analysis of the short Swift-BAT GRB 050202
  52. GRB 050202: Short burst detected by Swift-BAT
  53. GRB 050128 Optical observation with REM
  54. SGR1806-20: Swift-BAT detection of a large normal burst
  55. GRB 050128: near-infrared observations with REM
  56. GRB050128,optical observations
  57. GRB050128 Swift-BAT observations
  58. GRB 050128: Swift XRT prompt afterglow position
  59. GRB050126: MASTER optical limit for KECK OT
  60. GRB050126: Burst Parameters Measured by BAT
  61. GRB050126: MASTER optical observations
  62. GRB 050124 I-band observation
  63. GRB050124,optical observation
  64. GRB 050124 : Lulin R-band follow-up observation
  65. GRB050124: Updated Swift XRT Position and Fluxes
  66. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  67. GRB050124: Refined BAT position, spectral and fluence information
  68. GRB 050123 : I-band follow-up observation
  69. GRB050123,optical observation
  70. GRB 050123: KAIT observations
  71. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  72. GRB050117: Refined XRT position
  73. GRB050117: MASTER optical observations
  74. MASTER:GRB050117 SWIFT
  75. GRB050117: Swift XRT Position
  76. Triangulation of Short Hard GRB050112 (large error box)
  77. SGR 1806-20: Further VLA Observations
  78. SGR1806-20: Swift-BAT observations of two additional bursts
  79. SGR1806: Optical Transient Candidates in SOHO/LASCO Images
  80. Further VLA observations of SGR 1806-20
  81. SGR 1806-20 and extragalactic short-duration GRBs
  82. Further ATCA observations of SGR 1806-20
  83. Fourth Epoch VLA observations of SGR 1806-20
  84. SGR 1806-20: Low frequency GMRT results; submission to GCN circulars
  85. ATCA observations of SGR 1806-20
  86. SGR 1806-20, RHESSI observations of the 041227 giant flare
  87. Third epoch observations of SGR 1806-20 with VLA
  88. Second Epoch VLA observations of SGR 1806-20
  89. Second-epoch VLA observations of SGR 1806-20
  90. SGR1806 VLA Observations
  91. SGR1806-20: RXTE-PCA observation of the 041227 super-flare
  92. GRB 041217: Optical observations
  93. GRB041228: Swift-BAT detection of a burst
  94. GRB041219; RXTE ASM Observations
  95. NIR Observations of GRB 041219
  96. GRB041226: Swift-BAT detection of a burst
  97. GRB041223: decay of the afterglow
  98. GRB 041224: near-infrared observations with REM
  99. GRB 041223 Fluence measured by Swift-BAT
  100. GRB041223: optical and NIR observations with REM

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