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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"

43672 results found.

  1. GRB 050607: RTT150 optical observations
  2. GRB050607: refined analysis of prompt REM observations
  3. Swift/UVOT observations of GRB050607
  4. GRB 050607: PROMPT VRcIc Observations
  5. GRB050607: KAIT optical limits
  6. GRB 050525a, Mid-Infrared Observations
  7. GRB 050607: Optical decay and spectral slope
  8. GRB 050607 - XRT refined data analysis
  9. Optical Afterglow of GRB 050607
  10. GRB050607: Swift Detection of a long GRB
  11. GRB050607: P60 Observations
  12. GRB050607: prompt REM observations
  13. GRB 050603: prediction of t_break
  14. Limits on a SN in the field of GRB 050509b
  15. GRB 050603: Redshift
  16. GRB 050603 - XRT data analysis of the first day
  17. Konus-Wind observation of GRB 050603
  18. GRB 050603: Analysis of UVOT data
  19. GRB050603: Fading Afterglow observed by Swift UVOT
  20. GRB050603, submillimetre observations
  21. GRB 050603: Swift XRT Position
  22. GRB050603: Radio Detection
  23. GRB 050603: Swift-BAT refined analysis of a long three-spiked burst
  24. GRB 050603: Afterglow Identification from LCO
  25. GRB 050603: INTEGRAL shows it is not a short GRB
  26. Swift/BAT Detection of GRB050603
  27. GRB 050408: jet break in the XRT light curve
  28. GRB 050525a, infrared observations
  29. GRB 050525a, SMARTS optical/IR afterglow observations
  30. GRB050528, XRT observations
  31. GRB050528: updated Liverpool Telescope limits
  32. Swift-BAT GRB 050528: a soft burst
  33. Update on Swift-BAT GRB 050528 (Trigger 130679)
  34. GRB050528: BOOTES optical candidate (retraction)
  35. GRB050504: Ashra-P2/3 monitor and Ashra-AFT response
  36. GRB050528: BOOTES optical candidate
  37. Possible GRB050528: no candidate from Liverpool Telescope
  38. Swift-BAT detection of possible GRB 050528
  39. GRB050525a: Radio Observations
  40. GRB 050509b: refined XRT/Chandra afterglow position analysis
  41. GRB 050525: RTT150, Optical observations
  42. GRB050525a: optical upper limits
  43. GRB 050525a: SARA Observations
  44. GRB 050525B: Swift-BAT observations
  45. GRB 050525: MITSuME Optical Observation in VRI
  46. GRB 050525a: MDM Observations
  47. GRB050525A,optical observation
  48. GRB050525: Super-LOTIS observations
  49. GRB 050525, spectral lag pseudo-redshift
  50. GRB 050525a: Gemini/GMOS Spectra
  51. GRB050306: optical afterglow not confirmed
  52. GRB 050525A: BOOTES simultaneous optical observations
  53. GRB 050525A: Swift-BAT refined analysis
  54. GRB050525: Optical observations
  55. GRB 050525B: INTEGRAL shows it is unrelated to GRB050525A
  56. GRB 050525: pseudo-redshift
  57. Swift/UVOT UV and optical detections of GRB 050525
  58. Konus-Wind observation of GRB 050525
  59. GRB 050525: TAROT observations of the early afterglow
  60. INTEGRAL detection of GRB 050525
  61. GRB 050525, infrared observations
  62. GRB 050525: Optical observation
  63. GRB 050525: observatons of the optical afterglow
  64. GRB050525: ROTSE-III Refined Analysis
  65. GRB 050525 - Very Bright, Not Short
  66. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  67. GRB 050525A: ROTSE-III Detection of Possible Counterpart
  68. XRF050522: NIR observations of XRT candidate
  69. XRF 050522: Swift XRT refined analysis
  70. XRF050522: Radio Observations
  71. Swift/UVOT observation of XRF 050522
  72. GRB 050509A: Further I-band imaging
  73. GRB050522,optical observation
  74. GRB050520,optical observation
  75. XRF 050522: Continued NIR P200 Monitoring
  76. RBO Observations of GRB050522
  77. Recent GRB BVRcIc field photometry
  78. GRB050520: Radio Observations
  79. XRF 050522: Swift XRT observation
  80. XRF050522, BVRcIc field photometry
  81. XRF050522: Optical Observations
  82. XRF050522: Near-infrared Observations
  83. XRF 050522: KAIT observations
  84. XRF 050522 detected with INTEGRAL
  85. GRB 050520: VLT/ULTRACAM observations
  86. Swift UVOT Observations of GRB 050520
  87. GRB 050520: Swift XRT refined analysis
  88. XRF050509C: Chandra Afterglow Detection
  89. XRF 050509c: Swift XRT Upper Limit
  90. XRF050509c: Radio Observations
  91. RBO Observations of GRB050520
  92. GRB 050520: P200 Observations
  93. GRB050520: Liverpool Telescope follow-up
  94. RBO Observations of GRB050520
  95. GRB 050520: TAROT optical limit
  96. GRB 050520: Swift XRT position
  97. GRB 050520: VLT/ULTRACAM observations
  98. GRB 050520: OSN optical observations
  99. GRB 050520 - A long GRB detected with INTEGRAL
  100. No Swift-BAT Lightcurves in real-time for next 3 weeks

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