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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"

25228 results found.

  1. GRB 050306: further TAROT optical data
  2. GRB050309: Early optical limit from P60
  3. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  4. GRB 050309 : Lulin R-band observation
  5. Swift 107873: P60 Optical Observations
  6. GRB 050306: R-band observations
  7. GRB 050306: REM optical-infrared observations
  8. GRB 050306: Possible X-ray Afterglow Position from the Swift
  9. GRB 050306: TAROT optical observations
  10. GRB 050306,optical observation
  11. Ongoing activity of SGR 1806-20 after the giant flare
  12. GRB050215B: Late-Time Swift UVOT Observations
  13. PROMPT VRcIc Observations of GRB 050223
  14. XRF/GRB 050215B: Radio Observations
  15. XMM-Newton Images of GRB 050223
  16. GRB 050219b: candidate NIR afterglow
  17. Confirmed XRF nature for GRB050215b
  18. GRB050223 XMM-Newton observation
  19. INTEGRAL detection of GRB 050223
  20. GRB050223: ROTSE-III Optical Observations
  21. GRB 050223 Swift/BAT detection of a burst
  22. GRB 050223: Swift XRT Position
  23. HETE-2 Observations of GRB 050215b (=U11570): A Likely X-Ray Flash
  24. GRB050215b: Faulkes North and SDSS limits on UKIRT candidate
  25. GRB 050219a: Optical observations from LCO
  26. GRB 050219b: Optical and near-IR observations from LCO
  27. GRB 050219b: Swift-BAT detection of a burst
  28. GRB 050219b: CORRECTION: Swift XRT Position
  29. GRB 050219b: Swift XRT Position
  30. GRB 050219: Swift-BAT detection of a burst
  31. GRB 050215b: XRT confirmation of IR afterglow candidate
  32. GRB050215b: P60 Optical Observations
  33. GRB 050215b: Swift XRT Source Variability
  34. GRB 050215B: candidate afterglow
  35. GRB 050215b : Lulin follow-up observation
  36. GRB 050215b, BOOTES-2 simultaneous optical observations
  37. GRB050215A: ROTSE-III Optical Observations
  38. GRB050209: TAROT optical observations
  39. GRB 050209(=U11568): Duration and spectrum
  40. GRB050209: REM optical observations
  41. GRB 050209 I-band observation
  42. GRB 050209 Optical observations
  43. GRB050209: P60 Optical Observations
  44. GRB 050128: Radio observations
  45. Further analysis of the short Swift-BAT GRB 050202
  46. GRB 050202: Short burst detected by Swift-BAT
  47. GRB 050128 Optical observation with REM
  48. SGR1806-20: Swift-BAT detection of a large normal burst
  49. GRB 050128: near-infrared observations with REM
  50. GRB050128,optical observations
  51. GRB050128 Swift-BAT observations
  52. GRB 050128: Swift XRT prompt afterglow position
  53. GRB050126: MASTER optical limit for KECK OT
  54. GRB050126: Burst Parameters Measured by BAT
  55. GRB050126: MASTER optical observations
  56. GRB 050124 I-band observation
  57. GRB050124,optical observation
  58. GRB 050124 : Lulin R-band follow-up observation
  59. GRB050124: Updated Swift XRT Position and Fluxes
  60. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  61. GRB050124: Refined BAT position, spectral and fluence information
  62. GRB 050123 : I-band follow-up observation
  63. GRB050123,optical observation
  64. GRB 050123: KAIT observations
  65. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  66. GRB050117: Refined XRT position
  67. GRB050117: MASTER optical observations
  68. MASTER:GRB050117 SWIFT
  69. GRB050117: Swift XRT Position
  70. Triangulation of Short Hard GRB050112 (large error box)
  71. SGR 1806-20: Further VLA Observations
  72. SGR1806-20: Swift-BAT observations of two additional bursts
  73. SGR1806: Optical Transient Candidates in SOHO/LASCO Images
  74. Further VLA observations of SGR 1806-20
  75. SGR 1806-20 and extragalactic short-duration GRBs
  76. Further ATCA observations of SGR 1806-20
  77. Fourth Epoch VLA observations of SGR 1806-20
  78. SGR 1806-20: Low frequency GMRT results; submission to GCN circulars
  79. ATCA observations of SGR 1806-20
  80. SGR 1806-20, RHESSI observations of the 041227 giant flare
  81. Third epoch observations of SGR 1806-20 with VLA
  82. Second Epoch VLA observations of SGR 1806-20
  83. Second-epoch VLA observations of SGR 1806-20
  84. SGR1806 VLA Observations
  85. SGR1806-20: RXTE-PCA observation of the 041227 super-flare
  86. GRB 041217: Optical observations
  87. GRB041228: Swift-BAT detection of a burst
  88. GRB041219; RXTE ASM Observations
  89. NIR Observations of GRB 041219
  90. GRB041226: Swift-BAT detection of a burst
  91. GRB041223: decay of the afterglow
  92. GRB 041224: near-infrared observations with REM
  93. GRB 041223 Fluence measured by Swift-BAT
  94. GRB041223: optical and NIR observations with REM
  95. Swift-BAT Time History of GRB041219
  96. GRB 041219: TAROT optical observations
  97. GRB 041218: TAROT optical observations
  98. GRB 041223: J-band observations of the afterglow
  99. GRB 041219c: PROMPT Observations
  100. GRB041223: Swift-BAT detection of a bright long burst

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