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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"

26361 results found.

  1. GRB 050826 : Lulin R band observation
  2. GRB050824: Maidanak optical limits
  3. GRB 050827: Swift-BAT refined analysis
  4. Subaru Observations of GRB050724
  5. GRB 050826: Optical Candidate
  6. GRB 050826: Swift XRT preliminary analysis results
  7. GRB 050826: BAT refined analysis
  8. GRB050826: Swift/UVOT early upper limits
  9. GRB050826: Swift-BAT detection of a long burst
  10. GRB050824: MASTER final analysis of the OT observations
  11. Swift-BAT trigger 152038 is probably not a GRB
  12. GRB 050824: XRT refined analysis and possible afterglow detection
  13. GRB 050824: BAT refined analysis of a soft weak burst
  14. GRB050824: MASTER:OT decay
  15. GRB050824: MASTER observation OT
  16. GRB050805a: MASTER optical candidat
  17. XRF050509c: Radio upper limits from GMRT
  18. GRB050822: Swift/UVOT upper limits
  19. GRB 050820A BAT observations of second, larger episode of emission
  20. GRB050813: Maidanak I-band observations
  21. GRB 050822: Swift-BAT refined analysis
  22. GRB050525, GRB050607, GRB050802 BVRcIc field photometry
  23. GRB050820B at FRAM
  24. Swift/UVOT UV Photometry of GRB 050820B
  25. GRB 050822: Swift detection of a long burst
  26. GRB050820a BVRcIc field photometry
  27. GRB050820B XMM-Newton observation
  28. GRB 050820a: NIR Observations by WIRO
  29. GRB 050820B: Swift XRT position
  30. GRB050820B: Refined analysis of the Swift-BAT burst
  31. GRB050820: refined XRT analysis
  32. GRB 050820 Swift-BAT refined analysis
  33. GRB050819: refined XRT analysis
  34. GRB 050820: Swift detection of a GRB
  35. GRB 050819 Swift-BAT refined analysis
  36. GRB050819: Swift-BAT detection of a weak burst
  37. GRB 050817: Optical observations
  38. GRB050817: Negative Optical Observations
  39. GRB 050814: continued fading
  40. GRB050815: Optical afterglow detection by Swift UVOT
  41. GRB050815: XRT refined analysis
  42. GRB050815: Refined analysis of the Swift-BAT burst
  43. GRB 050815: ROTSE-III Optical Limits
  44. GRB050815: Swift-BAT detection of a burst
  45. GRB050814: Fading red source
  46. GRB050814: P60 Optical Afterglow Candidate
  47. GRB 050813: Non-fading of afterglow candidate
  48. GRB 050814: XRT refined analysis
  49. GRB050814: SWIFT/UVOT observation
  50. GRB050814: Refined analysis of the Swift-BAT burst
  51. GRB 050813: Gemini spectroscopy and redshifts of galaxies B and C
  52. GRB 050814: Swift XRT Afterglow Localization
  53. GRB 050814: Swift detection of a burst
  54. GRB 050813: Magellan detection of a high redshift galaxy cluster
  55. GRB050813, SDSS pre-burst observations
  56. GRB 050813: Swift-BAT refined analysis
  57. GRB 050813: Photometry of object in XRT error circle
  58. GRB050813: SWIFT/UVOT observation
  59. GRB 050813: Swift XRT afterglow localization
  60. Ongoing activity of SGR 1806-20: an intermediate burst 050811
  61. Detection of an intermediate burst from SGR 1806-20 on August 8
  62. GRB050805b: CrAO optical limit
  63. GRB050803, optical observations
  64. Retraction of Swift Trigger 149131 (GRB 050805B)
  65. GRB 050805b: OHP optical limits
  66. GRB 050805b: TAROT optical limits
  67. GRB050805b: MASTER optical observations
  68. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  69. GRB050805a: MASTER optical candidat
  70. GRB050802: TNG optical observations
  71. GRB050803: Radio Observation
  72. GRB 050803: RTT150 optical observations
  73. GRB050801: Radio Observation
  74. GRB050730: Radio Detection
  75. GRB 050803: Keck Observations
  76. GRB 050803: Swift-BAT refined analysis
  77. GRB 050802.422: Fading of the afterglow and detection of the host
  78. GRB 050803: early Swift XRT analysis results
  79. GRB 050803: TAROT optical limits
  80. GCN GRB observation 050713A
  81. GRB050730: FORS1 and UVES/VLT low- and high-resolution spectroscopy
  82. GRB050802 radio non-detection
  83. GRB 050730: OHP optical observations
  84. GRB 050802: early Swift XRT analysis results
  85. GRB 050802: Swift/UVOT observations
  86. GRB 050802: Swift-BAT refined analysis
  87. GRB050801: Optical photometry and decay index
  88. GRB 050802: Swift Gamma-ray Burst
  89. GRB050801: Swift/UVOT Optical and UV detections
  90. GRB 050730: Preliminary Analysis of MIKE Spectrum
  91. GCN 050801: early Swift XRT analysis results
  92. GRB 050801: Swift-BAT refined analysis
  93. GRB 050730: XRT refined analysis
  94. GRB 050730: early TAROT optical observations
  95. GRB 050730, spectra and optical photometry
  96. GRB050730: Refined BAT analysis of the Swift-BAT burst
  97. GRB 050730 XMM-Newton observation
  98. GRB050730: Swift-BAT detection of a weak burst
  99. GRB050713b: Maidanak optical observations
  100. GRB 050724: Secure Host Redshift from Keck

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