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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"

28044 results found.

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

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