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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"

26367 results found.

  1. Optical Afterglow of GRB 050607
  2. GRB050607: Swift Detection of a long GRB
  3. GRB050607: prompt REM observations
  4. Limits on a SN in the field of GRB 050509b
  5. GRB 050603 - XRT data analysis of the first day
  6. GRB050603, submillimetre observations
  7. GRB050603: Radio Detection
  8. GRB 050603: Swift-BAT refined analysis of a long three-spiked burst
  9. GRB 050603: INTEGRAL shows it is not a short GRB
  10. GRB 050525a, infrared observations
  11. GRB050528, XRT observations
  12. GRB050528: updated Liverpool Telescope limits
  13. Swift-BAT GRB 050528: a soft burst
  14. GRB050504: Ashra-P2/3 monitor and Ashra-AFT response
  15. Possible GRB050528: no candidate from Liverpool Telescope
  16. GRB050525a: Radio Observations
  17. GRB 050509b: refined XRT/Chandra afterglow position analysis
  18. GRB 050525: RTT150, Optical observations
  19. GRB 050525a: SARA Observations
  20. GRB 050525B: Swift-BAT observations
  21. GRB 050525: MITSuME Optical Observation in VRI
  22. GRB050525A,optical observation
  23. GRB050525: Super-LOTIS observations
  24. GRB 050525, spectral lag pseudo-redshift
  25. GRB050306: optical afterglow not confirmed
  26. GRB 050525: BART optical observation
  27. GRB 050525A: BOOTES simultaneous optical observations
  28. GRB 050525A: Swift-BAT refined analysis
  29. GRB050525: Optical observations
  30. GRB 050525B: INTEGRAL shows it is unrelated to GRB050525A
  31. Konus-Wind observation of GRB 050525
  32. GRB 050525: TAROT observations of the early afterglow
  33. INTEGRAL detection of GRB 050525
  34. GRB 050525, infrared observations
  35. GRB 050525: observatons of the optical afterglow
  36. GRB050525: ROTSE-III Refined Analysis
  37. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  38. XRF050522: Radio Observations
  39. Swift/UVOT observation of XRF 050522
  40. GRB 050509A: Further I-band imaging
  41. GRB050522,optical observation
  42. GRB050520,optical observation
  43. XRF 050522: Continued NIR P200 Monitoring
  44. RBO Observations of GRB050522
  45. Recent GRB BVRcIc field photometry
  46. GRB050520: Radio Observations
  47. XRF 050522: Swift XRT observation
  48. XRF050522, BVRcIc field photometry
  49. XRF050522: Optical Observations
  50. XRF050522: Near-infrared Observations
  51. GRB 050520: VLT/ULTRACAM observations
  52. GRB 050520: Swift XRT refined analysis
  53. XRF050509C: Chandra Afterglow Detection
  54. XRF050509c: Radio Observations
  55. GRB 050520: P200 Observations
  56. GRB 050520: TAROT optical limit
  57. GRB 050520: VLT/ULTRACAM observations
  58. XRF 050509c optical afterglow
  59. GRB 050509B and short GRB-SN association? (corrected)
  60. GRB 050509B and short GRB-SN association?
  61. GRB050502b: Early Observation
  62. GRB050509b, Bok telescope B-band imaging
  63. Refined Chandra analysis of GRB 050509b
  64. GRB050509b, SDSS pre-burst observations
  65. GRB 050509b: Keck/Chandra Cross-Correlation
  66. GRB 050509b: Keck/Chandra Cross-Correlation
  67. Chandra observation of GRB 050509b
  68. GRB 050509b: RAPTOR deep, early limits.
  69. GRB050509B: Optical observations at the Very Large Telescope
  70. GRB 050509b: No Optical Variability in XRT Error Circle
  71. GRB 050509a: Swift-BAT refined analysis
  72. GRB 050509c: ROTSE-III Optical Limits
  73. GRB 050505, early TAROT observation
  74. GRB050509c: REM NIR and Optical observations
  75. GRB 050509b: Physical Properties of the Candidate Host galaxy
  76. GRB 050505: SARA Observations
  77. GRB 050509B, Optical Observations
  78. GRB 050509B: Swift/XRT refined analysis
  79. GRB 050509b: Optical observations
  80. GRB 050509A: Optical observations
  81. GRB050509b: Radio Observations
  82. GRB 050509b: PAIRITEL and WIYN Observations
  83. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  84. Swift Detection of GRB050509b: A short duration burst
  85. Swift Detection of the Burst GRB050509
  86. GRB 050505: early time observations
  87. GRB 050505, simultaneous optical observation
  88. GRB050505: AAVSO observations
  89. GRB050416A : 1 GHz limit from GMRT
  90. GRB050505: Optical Afterglow Candidate
  91. GRB050505 Swift-BAT refined analysis
  92. GRB 050416b:Swift XRT afterglow upper limits
  93. GRB 050416b:Swift XRT afterglow upper limits
  94. GRB050502b: Afterglow Confirmation: Correction to OT Coordinates
  95. GRB050502b: Afterglow Confirmation
  96. GRB050502: P200 Observations (Correction)
  97. GRB050502: P200 Observations
  98. GRB 050504 : R band observation at Lulin observatory
  99. Swift UVOT observation of GRB 050504
  100. GRB 050504, R band Observations

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