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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"

8293 results found.

  1. GRB050824, I-band imaging
  2. GRB 050824: XRT refined analysis and possible afterglow detection
  3. GRB 050824: BAT refined analysis of a soft weak burst
  4. GRB050824: MASTER:OT decay
  5. GRB 050824 optical candidate
  6. GRB 050820a - corrections to GCN 3846
  7. Correction to Eiso calculation in GCN 3835 on GRB 050820A
  8. GRB050825a - very long GRB like GRB041219a? (Konus-Wind observation)
  9. GRB050814: P60 Optical Afterglow Candidate
  10. GRB 050813: Non-fading of afterglow candidate
  11. GRB 050814: Swift detection of a burst
  12. GRB050813, SDSS pre-burst observations
  13. GRB 050813: Possible Short Swift-BAT GRB
  14. Ongoing activity of SGR 1806-20: an intermediate burst 050811
  15. GRB050803: CrAO optical observations, no OT candidate
  16. Detection of an intermediate burst from SGR 1806-20 on August 8
  17. GRB050802: TNG optical observations
  18. GRB 050803: RTT150 optical observations
  19. GRB050803: CrAO optical observations, possible OT candidate
  20. GRB 050803, optical observations
  21. GRB 050802: Swift/UVOT optical and UV detections
  22. GRB050801: Optical photometry and decay index
  23. GRB 050730, SMARTS optical/IR afterglow observations
  24. GRB050730: Liverpool Telescope optical observations
  25. GRB 050730, optical candidate
  26. GRB 050724: Optical imaging/astrometry
  27. GRB 050721A: Swift-BAT refined analysis
  28. GRB 050721a: Optical Observations
  29. GRB 050714a: Refined XRT analysis and afterglow confirmation
  30. GRB 050716; J-band observations
  31. GRB 050716 - UKIRT identification of candidate afterglow
  32. GRB 050716: Refined XRT analysis.
  33. GRB050716: Faulkes North Telescope observation
  34. GRB 050714B: refined XRT analysis
  35. GRB 050714B: candidate afterglow does not fade
  36. GRB 050709: optical afterglow candidate
  37. GRB 050714, R-band candidate
  38. GRB 050709: Spectroscopy
  39. GRB 050713B: Swift-BAT Refined Analysis
  40. GRB050713B: Faulkes North Telescope observation
  41. RBO RI observations of GRB 050713A
  42. GRB050709: Candidate X-ray Afterglow from Chandra
  43. GRB 050713: ARC NIR Detections and Identification of Fading
  44. GRB050712: UVOT candidate optical counterpart
  45. GRB 050626: Swift XRT observations
  46. H3804: A Possible New XRB Detected by HETE
  47. Konus-Wind observation of an intermediate burst from SGR 1806-20
  48. GRB 050607: MDM Observations
  49. Limits on a SN in the field of GRB 050509b
  50. GRB 050603: Swift XRT Position
  51. GRB050528, XRT observations
  52. GRB050528: BOOTES optical candidate (retraction)
  53. GRB050528: BOOTES optical candidate
  54. Possible GRB050528: no candidate from Liverpool Telescope
  55. GRB050525: Super-LOTIS observations
  56. GRB 050525a: Gemini/GMOS Spectra
  57. GRB050306: optical afterglow not confirmed
  58. GRB050525: Optical observations
  59. GRB 050525: Optical observation
  60. XRF050522: NIR observations of XRT candidate
  61. XRF 050522: Swift XRT refined analysis
  62. XRF050522: Optical Observations
  63. GRB 050520: Swift XRT refined analysis
  64. XRF 050509c: Swift XRT Upper Limit
  65. GRB050520: Liverpool Telescope follow-up
  66. XRF 050509C: REM NIR and Optical refined analysis
  67. GRB 050504: Swift XRT afterglow candidate has faded
  68. XRF 050509c optical afterglow
  69. Chandra observation of GRB 050509b
  70. GRB 050509b: RAPTOR deep, early limits.
  71. GRB 050509b: Further Analysis of Keck LRIS Images
  72. GRB 050509b: Physical Properties of the Candidate Host galaxy
  73. GRB 050509B, Optical Observations
  74. GRB 050509B: Swift/XRT refined analysis
  75. GRB 050509b: Optical observations
  76. GRB 050509b: Optical Counterpart Candidate
  77. GRB 050505 - Faulkes Telescope North observations
  78. GRB 050502a: Swift XRT Upper Limit
  79. GRB050505: Infrared observations
  80. GRB050505: AAVSO observations
  81. GRB 050505: Keck absorption spectrum and redshift (z=4.27)
  82. GRB050505: Optical Afterglow Candidate
  83. GRB 050416b:Swift XRT afterglow upper limits
  84. GRB 050416b:Swift XRT afterglow upper limits
  85. GRB050502b: Afterglow Confirmation: Correction to OT Coordinates
  86. GRB050502b: Afterglow Confirmation
  87. Renewal of SGR 1806-20 activity
  88. GRB050502A: Optical Observations
  89. Swift UVOT refined analysis
  90. GRB 050502: Confirmed variability of the afterglow candidate +
  91. GRB050502 - Correction on the Optical Candidate from the Liverpool
  92. GRB050502 - Optical Candidate from the Liverpool Telescope
  93. Swift Detection of GRB 050422
  94. GRB 050421: NIR observations
  95. GRB 050416b: Tentative Swift XRT Position
  96. GRB 050416b: Swift-BAT refined analysis
  97. GRB050416: P200 NIR Observations
  98. GRB 050416: Swift XRT Position
  99. GRB 050416: Radio observations
  100. GRB050416: P60 Afterglow Candidate

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