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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"

25042 results found.

  1. GRB 050306: ROTSE-III early limits
  2. GRB050316: MASTER optical observations
  3. GRB 050315: Swift-BAT further refined analysis
  4. GRB 050315 I-band observations
  5. GRB050315: Radio afterglow
  6. GRB050315: Swift-BAT Refined analysis
  7. Non-detection of GRB050315 in ATCA Radio Observations
  8. GRB 050219b: Gemini/GNIRS near-infrared spectroscopy
  9. GRB 050315: Early Observations with Swift/UVOT
  10. GRB 050306: Radio Observations
  11. GRB050306: 250 GHz upper limit with MAMBO at the IRAM 30m
  12. GRB 050306: optical afterglow
  13. Swift-BAT trigger 107873: No Swift XRT counterpart
  14. GRB 050306: Confirmation of X-ray afterglow
  15. GRB 050306: further TAROT optical data
  16. GRB050309: Early optical limit from P60
  17. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  18. GRB 050309 : Lulin R-band observation
  19. Swift 107873: P60 Optical Observations
  20. GRB 050306: R-band observations
  21. GRB 050306: REM optical-infrared observations
  22. GRB 050306: Possible X-ray Afterglow Position from the Swift
  23. GRB 050306: TAROT optical observations
  24. GRB 050306,optical observation
  25. Ongoing activity of SGR 1806-20 after the giant flare
  26. GRB050215B: Late-Time Swift UVOT Observations
  27. PROMPT VRcIc Observations of GRB 050223
  28. XRF/GRB 050215B: Radio Observations
  29. XMM-Newton Images of GRB 050223
  30. GRB 050219b: candidate NIR afterglow
  31. Confirmed XRF nature for GRB050215b
  32. GRB050223 XMM-Newton observation
  33. INTEGRAL detection of GRB 050223
  34. GRB050223: ROTSE-III Optical Observations
  35. GRB 050223 Swift/BAT detection of a burst
  36. GRB 050223: Swift XRT Position
  37. HETE-2 Observations of GRB 050215b (=U11570): A Likely X-Ray Flash
  38. GRB050215b: Faulkes North and SDSS limits on UKIRT candidate
  39. GRB 050219a: Optical observations from LCO
  40. GRB 050219b: Optical and near-IR observations from LCO
  41. GRB 050219b: Swift-BAT detection of a burst
  42. GRB 050219b: CORRECTION: Swift XRT Position
  43. GRB 050219b: Swift XRT Position
  44. GRB 050219: Swift-BAT detection of a burst
  45. GRB 050215b: XRT confirmation of IR afterglow candidate
  46. GRB050215b: P60 Optical Observations
  47. GRB 050215b: Swift XRT Source Variability
  48. GRB 050215B: candidate afterglow
  49. GRB 050215b : Lulin follow-up observation
  50. GRB 050215b, BOOTES-2 simultaneous optical observations
  51. GRB050215A: ROTSE-III Optical Observations
  52. GRB050209: TAROT optical observations
  53. GRB 050209(=U11568): Duration and spectrum
  54. GRB050209: REM optical observations
  55. GRB 050209 I-band observation
  56. GRB 050209 Optical observations
  57. GRB050209: P60 Optical Observations
  58. GRB 050128: Radio observations
  59. Further analysis of the short Swift-BAT GRB 050202
  60. GRB 050202: Short burst detected by Swift-BAT
  61. GRB 050128 Optical observation with REM
  62. SGR1806-20: Swift-BAT detection of a large normal burst
  63. GRB 050128: near-infrared observations with REM
  64. GRB050128,optical observations
  65. GRB050128 Swift-BAT observations
  66. GRB 050128: Swift XRT prompt afterglow position
  67. GRB050126: MASTER optical limit for KECK OT
  68. GRB050126: Burst Parameters Measured by BAT
  69. GRB050126: MASTER optical observations
  70. GRB 050124 I-band observation
  71. GRB050124,optical observation
  72. GRB 050124 : Lulin R-band follow-up observation
  73. GRB050124: Updated Swift XRT Position and Fluxes
  74. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  75. GRB050124: Refined BAT position, spectral and fluence information
  76. GRB 050123 : I-band follow-up observation
  77. GRB050123,optical observation
  78. GRB 050123: KAIT observations
  79. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  80. GRB050117: Refined XRT position
  81. GRB050117: MASTER optical observations
  82. MASTER:GRB050117 SWIFT
  83. GRB050117: Swift XRT Position
  84. Triangulation of Short Hard GRB050112 (large error box)
  85. SGR 1806-20: Further VLA Observations
  86. SGR1806-20: Swift-BAT observations of two additional bursts
  87. SGR1806: Optical Transient Candidates in SOHO/LASCO Images
  88. Further VLA observations of SGR 1806-20
  89. SGR 1806-20 and extragalactic short-duration GRBs
  90. Further ATCA observations of SGR 1806-20
  91. Fourth Epoch VLA observations of SGR 1806-20
  92. SGR 1806-20: Low frequency GMRT results; submission to GCN circulars
  93. ATCA observations of SGR 1806-20
  94. SGR 1806-20, RHESSI observations of the 041227 giant flare
  95. Third epoch observations of SGR 1806-20 with VLA
  96. Second Epoch VLA observations of SGR 1806-20
  97. Second-epoch VLA observations of SGR 1806-20
  98. SGR1806 VLA Observations
  99. SGR1806-20: RXTE-PCA observation of the 041227 super-flare
  100. GRB 041217: Optical observations

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