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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"

28048 results found.

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

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