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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"

27774 results found.

  1. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  2. GRB 050309 : Lulin R-band observation
  3. Swift 107873: P60 Optical Observations
  4. GRB 050306: CORRECTION to date of observation
  5. GRB 050306: No Swift UVOT Optical Counterpart Detected
  6. GRB 050306: Possible X-ray Afterglow Position from the Swift
  7. Swift trigger 107518: optical observation
  8. GRB 050306,optical observation
  9. GRB 050306: Swift-BAT detection of a long burst
  10. GRB050215B: Late-Time Swift UVOT Observations
  11. PROMPT VRcIc Observations of GRB 050223
  12. GRB 050223: optical observations
  13. GRB050223 XMM-Newton observation
  14. INTEGRAL detection of GRB 050223
  15. GRB050223: No Swift UVOT Detection of Afterglow Emission
  16. GRB050223: ROTSE-III Optical Observations
  17. GRB 050223 Swift/BAT detection of a burst
  18. GRB 050223: Swift XRT Position
  19. GRB050219b: CORRECTION to time of UVOT observations
  20. GRB050215b: Faulkes North and SDSS limits on UKIRT candidate
  21. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  22. GRB 050219b: CORRECTION to refined XRT position
  23. GRB 050219b: Optical and near-IR observations from LCO
  24. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  25. GRB 050219b: Refined XRT position
  26. GRB 050219b: Swift-BAT detection of a burst
  27. GRB 050219b: CORRECTION: Swift XRT Position
  28. GRB 050219b: Swift XRT Position
  29. GRB 050219a, optical observations
  30. GRB 050219a: Refined XRT position
  31. GRB050219a: No Swift UVOT Detection of Afterglow Emission
  32. GRB 050219: Swift-BAT detection of a burst
  33. GRB050215b: Swift UVOT Detection of Afterglow Emission
  34. GRB 050219: Prompt X-ray position
  35. GRB 050215b: XRT confirmation of IR afterglow candidate
  36. GRB050215b: P60 Optical Observations
  37. GRB 050215b: Swift XRT Source Variability
  38. GRB 050215B: candidate afterglow
  39. GRB 050215b : Lulin follow-up observation
  40. GRB 050215b, BOOTES-2 simultaneous optical observations
  41. GRB 050215B: UKIRT K-band imaging
  42. GRB 050215b: Swift XRT Observations
  43. GRB050215b: No Swift UVOT Detection of Afterglow Emission
  44. GRB050215a: No Swift UVOT Detection of Afterglow Emission
  45. Swift-BAT detects two bursts: GRB050215a and GRB050215b
  46. GRB050215B: ROTSE-III optical observations
  47. GRB050215A: ROTSE-III Optical Observations
  48. short/hard GRB 050202, optical observations
  49. GRB 050128: Radio observations
  50. Further analysis of the short Swift-BAT GRB 050202
  51. GRB 050202: Second epoch radio observations
  52. GRB050202: Radio Observations
  53. GRB 050202: Short burst detected by Swift-BAT
  54. SGR1806-20: Swift-BAT detection of a large normal burst
  55. GRB050128: Faulkes Telescope South observations
  56. GRB 050128: near-infrared observations with REM
  57. GRB050128,optical observations
  58. GRB050126: Updated Swift XRT Position
  59. SGR 1806-20: GMRT results at 240 MHz band.
  60. SGR 1806-20: low frequency GMRT results of 2005 Jan 16.
  61. GRB 050126: Radio Observations
  62. GRB050128 Swift-BAT observations
  63. GRB 050128: Swift XRT prompt afterglow position
  64. GRB 050124: K-band afterglow observations
  65. GRB050126: MASTER optical limit for KECK OT
  66. GRB050126: Burst Parameters Measured by BAT
  67. GRB050126: MASTER optical observations
  68. GRB 050126: Detection of NIR afterglow with Keck/NIRC
  69. GRB 050126: Prompt XRT detection and localization
  70. GRB050124: No Swift UVOT Detection of Afterglow Emission
  71. GRB 050124, SMARTS optical/IR observations
  72. GRB 050117a: Radio Observations
  73. GRB050124,optical observation
  74. GRB050124: Updated Swift XRT Position and Fluxes
  75. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  76. GRB050124: Refined BAT position, spectral and fluence information
  77. GRB050124: Swift-BAT position of a double-peaked burst
  78. CFHTLS optical transient unlikely to be a GRB
  79. GRB050117a: Radio Observations
  80. GRB050117a: Refined analysis
  81. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  82. GRB050117b: Swift-BAT detection of a weak burst
  83. GRB050117: optical observation
  84. GRB 050117, I-band observations
  85. GRB 050117: Optical observation
  86. GRB050117: Refined XRT position
  87. GRB050117: MASTER optical observations
  88. MASTER:GRB050117 SWIFT
  89. GRB050117: Swift-BAT detection of a long multi-peaked burst
  90. GRB050117: Swift XRT Position
  91. SGR 1806-20: Further low frequency GMRT results
  92. SGR1806-20: Swift-BAT observations of two additional bursts
  93. SGR1806: Optical Transient Candidates in SOHO/LASCO Images
  94. SGR 1806-20: Low frequency GMRT results; submission to GCN circulars
  95. SGR 1806-20, RHESSI observations of the 041227 giant flare
  96. Second-epoch VLA observations of SGR 1806-20
  97. SGR1806: Detection of a Sudden Ionospheric Disturbance
  98. DETECTION OF POLARIZATION OF THE RADIO EMISSION FROM SGR 1806-20
  99. SGR1806 VLA Observations
  100. SGR1806-20: RXTE-PCA observation of the 041227 super-flare

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