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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"

28047 results found.

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

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