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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"

28047 results found.

  1. GRB050319,optical observation
  2. GRB 050318: Swift/UVOT detection of afterglow emission
  3. RXTE Observations of GRB050318
  4. GRB050223: analysis of the XMM-Newton observation
  5. GRB050316: MASTER before, simultanious and follow up optical
  6. GRB 050306: ROTSE-III early limits
  7. GRB050316: MASTER optical observations
  8. GRB 050315: Swift-BAT further refined analysis
  9. GRB 050315 I-band observations
  10. GRB050315: Radio afterglow
  11. GRB050315: Swift-BAT Refined analysis
  12. Non-detection of GRB050315 in ATCA Radio Observations
  13. GRB 050219b: Gemini/GNIRS near-infrared spectroscopy
  14. GRB 050315: Early Observations with Swift/UVOT
  15. GRB 050306: Radio Observations
  16. GRB050306: 250 GHz upper limit with MAMBO at the IRAM 30m
  17. GRB 050306: optical afterglow
  18. Swift-BAT trigger 107873: No Swift XRT counterpart
  19. GRB 050306: Confirmation of X-ray afterglow
  20. GRB 050306: further TAROT optical data
  21. GRB050309: Early optical limit from P60
  22. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  23. GRB 050309 : Lulin R-band observation
  24. Swift 107873: P60 Optical Observations
  25. GRB 050306: R-band observations
  26. GRB 050306: REM optical-infrared observations
  27. GRB 050306: Possible X-ray Afterglow Position from the Swift
  28. GRB 050306: TAROT optical observations
  29. GRB 050306,optical observation
  30. Ongoing activity of SGR 1806-20 after the giant flare
  31. GRB050215B: Late-Time Swift UVOT Observations
  32. PROMPT VRcIc Observations of GRB 050223
  33. XRF/GRB 050215B: Radio Observations
  34. XMM-Newton Images of GRB 050223
  35. GRB 050219b: candidate NIR afterglow
  36. Confirmed XRF nature for GRB050215b
  37. GRB050223 XMM-Newton observation
  38. INTEGRAL detection of GRB 050223
  39. GRB050223: ROTSE-III Optical Observations
  40. GRB 050223 Swift/BAT detection of a burst
  41. GRB 050223: Swift XRT Position
  42. HETE-2 Observations of GRB 050215b (=U11570): A Likely X-Ray Flash
  43. GRB050215b: Faulkes North and SDSS limits on UKIRT candidate
  44. GRB 050219a: Optical observations from LCO
  45. GRB 050219b: Optical and near-IR observations from LCO
  46. GRB 050219b: Swift-BAT detection of a burst
  47. GRB 050219b: CORRECTION: Swift XRT Position
  48. GRB 050219b: Swift XRT Position
  49. GRB 050219: Swift-BAT detection of a burst
  50. GRB 050215b: XRT confirmation of IR afterglow candidate
  51. GRB050215b: P60 Optical Observations
  52. GRB 050215b: Swift XRT Source Variability
  53. GRB 050215B: candidate afterglow
  54. GRB 050215b : Lulin follow-up observation
  55. GRB 050215b, BOOTES-2 simultaneous optical observations
  56. GRB050215A: ROTSE-III Optical Observations
  57. GRB050209: TAROT optical observations
  58. GRB 050209(=U11568): Duration and spectrum
  59. GRB050209: REM optical observations
  60. GRB 050209 I-band observation
  61. GRB 050209 Optical observations
  62. GRB050209: P60 Optical Observations
  63. GRB 050128: Radio observations
  64. Further analysis of the short Swift-BAT GRB 050202
  65. GRB 050202: Short burst detected by Swift-BAT
  66. GRB 050128 Optical observation with REM
  67. SGR1806-20: Swift-BAT detection of a large normal burst
  68. GRB 050128: near-infrared observations with REM
  69. GRB050128,optical observations
  70. GRB050128 Swift-BAT observations
  71. GRB 050128: Swift XRT prompt afterglow position
  72. GRB050126: MASTER optical limit for KECK OT
  73. GRB050126: Burst Parameters Measured by BAT
  74. GRB050126: MASTER optical observations
  75. GRB 050124 I-band observation
  76. GRB050124,optical observation
  77. GRB 050124 : Lulin R-band follow-up observation
  78. GRB050124: Updated Swift XRT Position and Fluxes
  79. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  80. GRB050124: Refined BAT position, spectral and fluence information
  81. GRB 050123 : I-band follow-up observation
  82. GRB050123,optical observation
  83. GRB 050123: KAIT observations
  84. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  85. GRB050117: Refined XRT position
  86. GRB050117: MASTER optical observations
  87. MASTER:GRB050117 SWIFT
  88. GRB050117: Swift XRT Position
  89. Triangulation of Short Hard GRB050112 (large error box)
  90. SGR 1806-20: Further VLA Observations
  91. SGR1806-20: Swift-BAT observations of two additional bursts
  92. SGR1806: Optical Transient Candidates in SOHO/LASCO Images
  93. Further VLA observations of SGR 1806-20
  94. SGR 1806-20 and extragalactic short-duration GRBs
  95. Further ATCA observations of SGR 1806-20
  96. Fourth Epoch VLA observations of SGR 1806-20
  97. SGR 1806-20: Low frequency GMRT results; submission to GCN circulars
  98. ATCA observations of SGR 1806-20
  99. SGR 1806-20, RHESSI observations of the 041227 giant flare
  100. Third epoch observations of SGR 1806-20 with VLA

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