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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"

26350 results found.

  1. GRB 050824: XRT refined analysis and possible afterglow detection
  2. GRB 050824: BAT refined analysis of a soft weak burst
  3. GRB050824: MASTER:OT decay
  4. GRB050824: MASTER observation OT
  5. GRB050805a: MASTER optical candidat
  6. XRF050509c: Radio upper limits from GMRT
  7. GRB050822: Swift/UVOT upper limits
  8. GRB 050820A BAT observations of second, larger episode of emission
  9. GRB050813: Maidanak I-band observations
  10. GRB 050822: Swift-BAT refined analysis
  11. GRB050525, GRB050607, GRB050802 BVRcIc field photometry
  12. GRB050820B at FRAM
  13. Swift/UVOT UV Photometry of GRB 050820B
  14. GRB 050822: Swift detection of a long burst
  15. GRB050820a BVRcIc field photometry
  16. GRB050820B XMM-Newton observation
  17. GRB 050820a: NIR Observations by WIRO
  18. GRB 050820B: Swift XRT position
  19. GRB050820B: Refined analysis of the Swift-BAT burst
  20. GRB050820: refined XRT analysis
  21. GRB 050820 Swift-BAT refined analysis
  22. GRB050819: refined XRT analysis
  23. GRB 050820: Swift detection of a GRB
  24. GRB 050819 Swift-BAT refined analysis
  25. GRB050819: Swift-BAT detection of a weak burst
  26. GRB 050817: Optical observations
  27. GRB050817: Negative Optical Observations
  28. GRB 050814: continued fading
  29. GRB050815: Optical afterglow detection by Swift UVOT
  30. GRB050815: XRT refined analysis
  31. GRB050815: Refined analysis of the Swift-BAT burst
  32. GRB 050815: ROTSE-III Optical Limits
  33. GRB050815: Swift-BAT detection of a burst
  34. GRB050814: Fading red source
  35. GRB050814: P60 Optical Afterglow Candidate
  36. GRB 050813: Non-fading of afterglow candidate
  37. GRB 050814: XRT refined analysis
  38. GRB050814: SWIFT/UVOT observation
  39. GRB050814: Refined analysis of the Swift-BAT burst
  40. GRB 050813: Gemini spectroscopy and redshifts of galaxies B and C
  41. GRB 050814: Swift XRT Afterglow Localization
  42. GRB 050814: Swift detection of a burst
  43. GRB 050813: Magellan detection of a high redshift galaxy cluster
  44. GRB050813, SDSS pre-burst observations
  45. GRB 050813: Swift-BAT refined analysis
  46. GRB 050813: Photometry of object in XRT error circle
  47. GRB050813: SWIFT/UVOT observation
  48. GRB 050813: Swift XRT afterglow localization
  49. Ongoing activity of SGR 1806-20: an intermediate burst 050811
  50. Detection of an intermediate burst from SGR 1806-20 on August 8
  51. GRB050805b: CrAO optical limit
  52. GRB050803, optical observations
  53. Retraction of Swift Trigger 149131 (GRB 050805B)
  54. GRB 050805b: OHP optical limits
  55. GRB 050805b: TAROT optical limits
  56. GRB050805b: MASTER optical observations
  57. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  58. GRB050805a: MASTER optical candidat
  59. GRB050802: TNG optical observations
  60. GRB050803: Radio Observation
  61. GRB 050803: RTT150 optical observations
  62. GRB050801: Radio Observation
  63. GRB050730: Radio Detection
  64. GRB 050803: Keck Observations
  65. GRB 050803: Swift-BAT refined analysis
  66. GRB 050802.422: Fading of the afterglow and detection of the host
  67. GRB 050803: early Swift XRT analysis results
  68. GRB 050803: TAROT optical limits
  69. GCN GRB observation 050713A
  70. GRB050730: FORS1 and UVES/VLT low- and high-resolution spectroscopy
  71. GRB050802 radio non-detection
  72. GRB 050730: OHP optical observations
  73. GRB 050802: early Swift XRT analysis results
  74. GRB 050802: Swift/UVOT observations
  75. GRB 050802: Swift-BAT refined analysis
  76. GRB050801: Optical photometry and decay index
  77. GRB 050802: Swift Gamma-ray Burst
  78. GRB050801: Swift/UVOT Optical and UV detections
  79. GRB 050730: Preliminary Analysis of MIKE Spectrum
  80. GCN 050801: early Swift XRT analysis results
  81. GRB 050801: Swift-BAT refined analysis
  82. GRB 050730: XRT refined analysis
  83. GRB 050730: early TAROT optical observations
  84. GRB 050730, spectra and optical photometry
  85. GRB050730: Refined BAT analysis of the Swift-BAT burst
  86. GRB 050730 XMM-Newton observation
  87. GRB050730: Swift-BAT detection of a weak burst
  88. GRB050713b: Maidanak optical observations
  89. GRB 050724: Secure Host Redshift from Keck
  90. GRB 050724: WHT optical observations
  91. GRB050713: analysis of the XMM-Newton observation
  92. Swift-BAT trigger 147918 is not a real GRB
  93. GRB050724: VLT observations of the variable source
  94. GRB050709: Second Epoch Chandra Observation
  95. GRB050726: Swift-BAT detection of a weak burst
  96. GRB 050724: Optical Variability in Nearby Galaxy
  97. GRB 050724: J-band observations
  98. GRB 050724: GMOS Imaging and Spectroscopy
  99. GRB050724: Radio Observation
  100. GRB 050724: Optical imaging/astrometry

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