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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"

28043 results found.

  1. GRB 050820A BAT observations of second, larger episode of emission
  2. GRB050813: Maidanak I-band observations
  3. GRB 050822: Swift-BAT refined analysis
  4. GRB050525, GRB050607, GRB050802 BVRcIc field photometry
  5. GRB050820B at FRAM
  6. Swift/UVOT UV Photometry of GRB 050820B
  7. GRB 050822: Swift detection of a long burst
  8. GRB050820a BVRcIc field photometry
  9. GRB050820B XMM-Newton observation
  10. GRB 050820a: NIR Observations by WIRO
  11. GRB 050820B: Swift XRT position
  12. GRB050820B: Refined analysis of the Swift-BAT burst
  13. GRB050820: refined XRT analysis
  14. GRB 050820 Swift-BAT refined analysis
  15. GRB050819: refined XRT analysis
  16. GRB 050820: Swift detection of a GRB
  17. GRB 050819 Swift-BAT refined analysis
  18. GRB050819: Swift-BAT detection of a weak burst
  19. GRB 050817: Optical observations
  20. GRB050817: Negative Optical Observations
  21. GRB 050814: continued fading
  22. GRB050815: Optical afterglow detection by Swift UVOT
  23. GRB050815: XRT refined analysis
  24. GRB050815: Refined analysis of the Swift-BAT burst
  25. GRB 050815: ROTSE-III Optical Limits
  26. GRB050815: Swift-BAT detection of a burst
  27. GRB050814: Fading red source
  28. GRB050814: P60 Optical Afterglow Candidate
  29. GRB 050813: Non-fading of afterglow candidate
  30. GRB 050814: XRT refined analysis
  31. GRB050814: SWIFT/UVOT observation
  32. GRB050814: Refined analysis of the Swift-BAT burst
  33. GRB 050813: Gemini spectroscopy and redshifts of galaxies B and C
  34. GRB 050814: Swift XRT Afterglow Localization
  35. GRB 050814: Swift detection of a burst
  36. GRB 050813: Magellan detection of a high redshift galaxy cluster
  37. GRB050813, SDSS pre-burst observations
  38. GRB 050813: Swift-BAT refined analysis
  39. GRB 050813: Photometry of object in XRT error circle
  40. GRB050813: SWIFT/UVOT observation
  41. GRB 050813: Swift XRT afterglow localization
  42. Ongoing activity of SGR 1806-20: an intermediate burst 050811
  43. Detection of an intermediate burst from SGR 1806-20 on August 8
  44. GRB050805b: CrAO optical limit
  45. GRB050803, optical observations
  46. Retraction of Swift Trigger 149131 (GRB 050805B)
  47. GRB 050805b: OHP optical limits
  48. GRB 050805b: TAROT optical limits
  49. GRB050805b: MASTER optical observations
  50. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  51. GRB050805a: MASTER optical candidat
  52. GRB050802: TNG optical observations
  53. GRB050803: Radio Observation
  54. GRB 050803: RTT150 optical observations
  55. GRB050801: Radio Observation
  56. GRB050730: Radio Detection
  57. GRB 050803: Keck Observations
  58. GRB 050803: Swift-BAT refined analysis
  59. GRB 050802.422: Fading of the afterglow and detection of the host
  60. GRB 050803: early Swift XRT analysis results
  61. GRB 050803: TAROT optical limits
  62. GCN GRB observation 050713A
  63. GRB050730: FORS1 and UVES/VLT low- and high-resolution spectroscopy
  64. GRB050802 radio non-detection
  65. GRB 050730: OHP optical observations
  66. GRB 050802: early Swift XRT analysis results
  67. GRB 050802: Swift/UVOT observations
  68. GRB 050802: Swift-BAT refined analysis
  69. GRB050801: Optical photometry and decay index
  70. GRB 050802: Swift Gamma-ray Burst
  71. GRB050801: Swift/UVOT Optical and UV detections
  72. GRB 050730: Preliminary Analysis of MIKE Spectrum
  73. GCN 050801: early Swift XRT analysis results
  74. GRB 050801: Swift-BAT refined analysis
  75. GRB 050730: XRT refined analysis
  76. GRB 050730: early TAROT optical observations
  77. GRB 050730, spectra and optical photometry
  78. GRB050730: Refined BAT analysis of the Swift-BAT burst
  79. GRB 050730 XMM-Newton observation
  80. GRB050730: Swift-BAT detection of a weak burst
  81. GRB050713b: Maidanak optical observations
  82. GRB 050724: Secure Host Redshift from Keck
  83. GRB 050724: WHT optical observations
  84. GRB050713: analysis of the XMM-Newton observation
  85. Swift-BAT trigger 147918 is not a real GRB
  86. GRB050724: VLT observations of the variable source
  87. GRB050709: Second Epoch Chandra Observation
  88. GRB050726: Swift-BAT detection of a weak burst
  89. GRB 050724: Optical Variability in Nearby Galaxy
  90. GRB 050724: J-band observations
  91. GRB 050724: GMOS Imaging and Spectroscopy
  92. GRB050724: Radio Observation
  93. GRB 050724: Optical imaging/astrometry
  94. GRB 050724: Swift/UVOT Upper Limit
  95. GRB050724: Refined analysis of the Swift-BAT possible short burst
  96. GRB 050724: possible host galaxy in DSS
  97. GRB 050721A: Swift-BAT refined analysis
  98. GRB 050721A: Early Swift XRT analysis results
  99. GRB050721A: optical decay
  100. GRB 050721: optical afterglow confirmed

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