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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"

26344 results found.

  1. GRB050822: Swift/UVOT upper limits
  2. GRB 050820A BAT observations of second, larger episode of emission
  3. GRB050813: Maidanak I-band observations
  4. GRB 050822: Swift-BAT refined analysis
  5. GRB050525, GRB050607, GRB050802 BVRcIc field photometry
  6. GRB050820B at FRAM
  7. Swift/UVOT UV Photometry of GRB 050820B
  8. GRB 050822: Swift detection of a long burst
  9. GRB050820a BVRcIc field photometry
  10. GRB050820B XMM-Newton observation
  11. GRB 050820a: NIR Observations by WIRO
  12. GRB 050820B: Swift XRT position
  13. GRB050820B: Refined analysis of the Swift-BAT burst
  14. GRB050820: refined XRT analysis
  15. GRB 050820 Swift-BAT refined analysis
  16. GRB050819: refined XRT analysis
  17. GRB 050820: Swift detection of a GRB
  18. GRB 050819 Swift-BAT refined analysis
  19. GRB050819: Swift-BAT detection of a weak burst
  20. GRB 050817: Optical observations
  21. GRB050817: Negative Optical Observations
  22. GRB 050814: continued fading
  23. GRB050815: Optical afterglow detection by Swift UVOT
  24. GRB050815: XRT refined analysis
  25. GRB050815: Refined analysis of the Swift-BAT burst
  26. GRB 050815: ROTSE-III Optical Limits
  27. GRB050815: Swift-BAT detection of a burst
  28. GRB050814: Fading red source
  29. GRB050814: P60 Optical Afterglow Candidate
  30. GRB 050813: Non-fading of afterglow candidate
  31. GRB 050814: XRT refined analysis
  32. GRB050814: SWIFT/UVOT observation
  33. GRB050814: Refined analysis of the Swift-BAT burst
  34. GRB 050813: Gemini spectroscopy and redshifts of galaxies B and C
  35. GRB 050814: Swift XRT Afterglow Localization
  36. GRB 050814: Swift detection of a burst
  37. GRB 050813: Magellan detection of a high redshift galaxy cluster
  38. GRB050813, SDSS pre-burst observations
  39. GRB 050813: Swift-BAT refined analysis
  40. GRB 050813: Photometry of object in XRT error circle
  41. GRB050813: SWIFT/UVOT observation
  42. GRB 050813: Swift XRT afterglow localization
  43. Ongoing activity of SGR 1806-20: an intermediate burst 050811
  44. Detection of an intermediate burst from SGR 1806-20 on August 8
  45. GRB050805b: CrAO optical limit
  46. GRB050803, optical observations
  47. Retraction of Swift Trigger 149131 (GRB 050805B)
  48. GRB 050805b: OHP optical limits
  49. GRB 050805b: TAROT optical limits
  50. GRB050805b: MASTER optical observations
  51. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  52. GRB050805a: MASTER optical candidat
  53. GRB050802: TNG optical observations
  54. GRB050803: Radio Observation
  55. GRB 050803: RTT150 optical observations
  56. GRB050801: Radio Observation
  57. GRB050730: Radio Detection
  58. GRB 050803: Keck Observations
  59. GRB 050803: Swift-BAT refined analysis
  60. GRB 050802.422: Fading of the afterglow and detection of the host
  61. GRB 050803: early Swift XRT analysis results
  62. GRB 050803: TAROT optical limits
  63. GCN GRB observation 050713A
  64. GRB050730: FORS1 and UVES/VLT low- and high-resolution spectroscopy
  65. GRB050802 radio non-detection
  66. GRB 050730: OHP optical observations
  67. GRB 050802: early Swift XRT analysis results
  68. GRB 050802: Swift/UVOT observations
  69. GRB 050802: Swift-BAT refined analysis
  70. GRB050801: Optical photometry and decay index
  71. GRB 050802: Swift Gamma-ray Burst
  72. GRB050801: Swift/UVOT Optical and UV detections
  73. GRB 050730: Preliminary Analysis of MIKE Spectrum
  74. GCN 050801: early Swift XRT analysis results
  75. GRB 050801: Swift-BAT refined analysis
  76. GRB 050730: XRT refined analysis
  77. GRB 050730: early TAROT optical observations
  78. GRB 050730, spectra and optical photometry
  79. GRB050730: Refined BAT analysis of the Swift-BAT burst
  80. GRB 050730 XMM-Newton observation
  81. GRB050730: Swift-BAT detection of a weak burst
  82. GRB050713b: Maidanak optical observations
  83. GRB 050724: Secure Host Redshift from Keck
  84. GRB 050724: WHT optical observations
  85. GRB050713: analysis of the XMM-Newton observation
  86. Swift-BAT trigger 147918 is not a real GRB
  87. GRB050724: VLT observations of the variable source
  88. GRB050709: Second Epoch Chandra Observation
  89. GRB050726: Swift-BAT detection of a weak burst
  90. GRB 050724: Optical Variability in Nearby Galaxy
  91. GRB 050724: J-band observations
  92. GRB 050724: GMOS Imaging and Spectroscopy
  93. GRB050724: Radio Observation
  94. GRB 050724: Optical imaging/astrometry
  95. GRB 050724: Swift/UVOT Upper Limit
  96. GRB050724: Refined analysis of the Swift-BAT possible short burst
  97. GRB 050724: possible host galaxy in DSS
  98. GRB 050721A: Swift-BAT refined analysis
  99. GRB 050721A: Early Swift XRT analysis results
  100. GRB050721A: optical decay

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