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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"

45713 results found.

  1. GRB 050603: Redshift
  2. GRB 050603 - XRT data analysis of the first day
  3. Konus-Wind observation of GRB 050603
  4. GRB 050603: Analysis of UVOT data
  5. GRB050603: Fading Afterglow observed by Swift UVOT
  6. GRB050603, submillimetre observations
  7. GRB 050603: Swift XRT Position
  8. GRB050603: Radio Detection
  9. GRB 050603: Swift-BAT refined analysis of a long three-spiked burst
  10. GRB 050603: Afterglow Identification from LCO
  11. GRB 050603: INTEGRAL shows it is not a short GRB
  12. Swift/BAT Detection of GRB050603
  13. GRB 050408: jet break in the XRT light curve
  14. GRB 050525a, infrared observations
  15. GRB 050525a, SMARTS optical/IR afterglow observations
  16. GRB050528, XRT observations
  17. Correction to GCN Circ 3502 on GRB 050528
  18. GRB050528: updated Liverpool Telescope limits
  19. Swift-BAT GRB 050528: a soft burst
  20. Update on Swift-BAT GRB 050528 (Trigger 130679)
  21. GRB050528: BOOTES optical candidate (retraction)
  22. GRB050504: Ashra-P2/3 monitor and Ashra-AFT response
  23. GRB050528: BOOTES optical candidate
  24. Possible GRB050528: no candidate from Liverpool Telescope
  25. Swift-BAT detection of possible GRB 050528
  26. GRB050525a: Radio Observations
  27. GRB 050509b: refined XRT/Chandra afterglow position analysis
  28. GRB 050525: RTT150, Optical observations
  29. GRB050525a: optical upper limits
  30. GRB 050525a: SARA Observations
  31. GRB 050525B: Swift-BAT observations
  32. GRB 050525: MITSuME Optical Observation in VRI
  33. GRB 050525a: MDM Observations
  34. GRB050525A,optical observation
  35. GRB 050525 : Lulin optical afterglow observations
  36. GRB050525: Super-LOTIS observations
  37. GRB 050525, spectral lag pseudo-redshift
  38. GRB 050525a: Gemini/GMOS Spectra
  39. GRB050306: optical afterglow not confirmed
  40. GRB 050525: BART optical observation
  41. GRB 050525A: BOOTES simultaneous optical observations
  42. GRB 050525A: Swift-BAT refined analysis
  43. GRB050525: Optical observations
  44. GRB 050525B: INTEGRAL shows it is unrelated to GRB050525A
  45. GRB 050525: pseudo-redshift
  46. Swift/UVOT UV and optical detections of GRB 050525
  47. Konus-Wind observation of GRB 050525
  48. GRB 050525: TAROT observations of the early afterglow
  49. INTEGRAL detection of GRB 050525
  50. GRB 050525, infrared observations
  51. GRB 050525: Optical observation
  52. GRB 050525: observatons of the optical afterglow
  53. GRB050525: ROTSE-III Refined Analysis
  54. GRB 050525 - Very Bright, Not Short
  55. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  56. GRB 050525A: ROTSE-III Detection of Possible Counterpart
  57. XRF050522: NIR observations of XRT candidate
  58. XRF 050522: Swift XRT refined analysis
  59. XRF050522: Radio Observations
  60. Swift/UVOT observation of XRF 050522
  61. GRB 050509A: Further I-band imaging
  62. GRB050522,optical observation
  63. GRB050520,optical observation
  64. XRF 050522: Continued NIR P200 Monitoring
  65. RBO Observations of GRB050522
  66. GRB050509b: optical observations
  67. Recent GRB BVRcIc field photometry
  68. GRB050520: Radio Observations
  69. XRF 050522: Swift XRT observation
  70. XRF050522, BVRcIc field photometry
  71. XRF 050522 : Lulin observations
  72. XRF050522: Optical Observations
  73. XRF050522: Near-infrared Observations
  74. XRF 050522: KAIT observations
  75. XRF 050522 detected with INTEGRAL
  76. GRB 050520: VLT/ULTRACAM observations
  77. Swift UVOT Observations of GRB 050520
  78. GRB 050520: Swift XRT refined analysis
  79. XRF050509C: Chandra Afterglow Detection
  80. XRF 050509c: Swift XRT Upper Limit
  81. XRF050509c: Radio Observations
  82. RBO Observations of GRB050520
  83. GRB 050520: P200 Observations
  84. GRB050520: Liverpool Telescope follow-up
  85. RBO Observations of GRB050520
  86. GRB 050520: TAROT optical limit
  87. GRB 050520: Swift XRT position
  88. GRB 050520: VLT/ULTRACAM observations
  89. GRB 050520: OSN optical observations
  90. GRB 050520: BART optical limit
  91. GRB 050520 - A long GRB detected with INTEGRAL
  92. No Swift-BAT Lightcurves in real-time for next 3 weeks
  93. Swift-BAT trigger 122203 is not a real GRB
  94. XRF 050509C: REM NIR and Optical refined analysis
  95. GRB 050504: Swift XRT afterglow candidate has faded
  96. XRF 050509c optical afterglow
  97. GRB 050509B and short GRB-SN association? (corrected)
  98. GRB 050509B and short GRB-SN association?
  99. GRB 050509B: Subaru Optical Observations
  100. GRB050502b: Early Observation

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