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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"

28046 results found.

  1. GRB050805a: MASTER optical candidat
  2. XRF050509c: Radio upper limits from GMRT
  3. GRB050822: Swift/UVOT upper limits
  4. GRB 050820A BAT observations of second, larger episode of emission
  5. GRB050813: Maidanak I-band observations
  6. GRB 050822: Swift-BAT refined analysis
  7. GRB050525, GRB050607, GRB050802 BVRcIc field photometry
  8. GRB050820B at FRAM
  9. Swift/UVOT UV Photometry of GRB 050820B
  10. GRB 050822: Swift detection of a long burst
  11. GRB050820a BVRcIc field photometry
  12. GRB050820B XMM-Newton observation
  13. GRB 050820a: NIR Observations by WIRO
  14. GRB 050820B: Swift XRT position
  15. GRB050820B: Refined analysis of the Swift-BAT burst
  16. GRB050820: refined XRT analysis
  17. GRB 050820 Swift-BAT refined analysis
  18. GRB050819: refined XRT analysis
  19. GRB 050820: Swift detection of a GRB
  20. GRB 050819 Swift-BAT refined analysis
  21. GRB050819: Swift-BAT detection of a weak burst
  22. GRB 050817: Optical observations
  23. GRB050817: Negative Optical Observations
  24. GRB 050814: continued fading
  25. GRB050815: Optical afterglow detection by Swift UVOT
  26. GRB050815: XRT refined analysis
  27. GRB050815: Refined analysis of the Swift-BAT burst
  28. GRB 050815: ROTSE-III Optical Limits
  29. GRB050815: Swift-BAT detection of a burst
  30. GRB050814: Fading red source
  31. GRB050814: P60 Optical Afterglow Candidate
  32. GRB 050813: Non-fading of afterglow candidate
  33. GRB 050814: XRT refined analysis
  34. GRB050814: SWIFT/UVOT observation
  35. GRB050814: Refined analysis of the Swift-BAT burst
  36. GRB 050813: Gemini spectroscopy and redshifts of galaxies B and C
  37. GRB 050814: Swift XRT Afterglow Localization
  38. GRB 050814: Swift detection of a burst
  39. GRB 050813: Magellan detection of a high redshift galaxy cluster
  40. GRB050813, SDSS pre-burst observations
  41. GRB 050813: Swift-BAT refined analysis
  42. GRB 050813: Photometry of object in XRT error circle
  43. GRB050813: SWIFT/UVOT observation
  44. GRB 050813: Swift XRT afterglow localization
  45. Ongoing activity of SGR 1806-20: an intermediate burst 050811
  46. Detection of an intermediate burst from SGR 1806-20 on August 8
  47. GRB050805b: CrAO optical limit
  48. GRB050803, optical observations
  49. Retraction of Swift Trigger 149131 (GRB 050805B)
  50. GRB 050805b: OHP optical limits
  51. GRB 050805b: TAROT optical limits
  52. GRB050805b: MASTER optical observations
  53. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  54. GRB050805a: MASTER optical candidat
  55. GRB050802: TNG optical observations
  56. GRB050803: Radio Observation
  57. GRB 050803: RTT150 optical observations
  58. GRB050801: Radio Observation
  59. GRB050730: Radio Detection
  60. GRB 050803: Keck Observations
  61. GRB 050803: Swift-BAT refined analysis
  62. GRB 050802.422: Fading of the afterglow and detection of the host
  63. GRB 050803: early Swift XRT analysis results
  64. GRB 050803: TAROT optical limits
  65. GCN GRB observation 050713A
  66. GRB050730: FORS1 and UVES/VLT low- and high-resolution spectroscopy
  67. GRB050802 radio non-detection
  68. GRB 050730: OHP optical observations
  69. GRB 050802: early Swift XRT analysis results
  70. GRB 050802: Swift/UVOT observations
  71. GRB 050802: Swift-BAT refined analysis
  72. GRB050801: Optical photometry and decay index
  73. GRB 050802: Swift Gamma-ray Burst
  74. GRB050801: Swift/UVOT Optical and UV detections
  75. GRB 050730: Preliminary Analysis of MIKE Spectrum
  76. GCN 050801: early Swift XRT analysis results
  77. GRB 050801: Swift-BAT refined analysis
  78. GRB 050730: XRT refined analysis
  79. GRB 050730: early TAROT optical observations
  80. GRB 050730, spectra and optical photometry
  81. GRB050730: Refined BAT analysis of the Swift-BAT burst
  82. GRB 050730 XMM-Newton observation
  83. GRB050730: Swift-BAT detection of a weak burst
  84. GRB050713b: Maidanak optical observations
  85. GRB 050724: Secure Host Redshift from Keck
  86. GRB 050724: WHT optical observations
  87. GRB050713: analysis of the XMM-Newton observation
  88. Swift-BAT trigger 147918 is not a real GRB
  89. GRB050724: VLT observations of the variable source
  90. GRB050709: Second Epoch Chandra Observation
  91. GRB050726: Swift-BAT detection of a weak burst
  92. GRB 050724: Optical Variability in Nearby Galaxy
  93. GRB 050724: J-band observations
  94. GRB 050724: GMOS Imaging and Spectroscopy
  95. GRB050724: Radio Observation
  96. GRB 050724: Optical imaging/astrometry
  97. GRB 050724: Swift/UVOT Upper Limit
  98. GRB050724: Refined analysis of the Swift-BAT possible short burst
  99. GRB 050724: possible host galaxy in DSS
  100. GRB 050721A: Swift-BAT refined analysis

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