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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"

26359 results found.

  1. GRB 050603: INTEGRAL shows it is not a short GRB
  2. GRB 050525a, infrared observations
  3. GRB050528, XRT observations
  4. GRB050528: updated Liverpool Telescope limits
  5. Swift-BAT GRB 050528: a soft burst
  6. GRB050504: Ashra-P2/3 monitor and Ashra-AFT response
  7. Possible GRB050528: no candidate from Liverpool Telescope
  8. GRB050525a: Radio Observations
  9. GRB 050509b: refined XRT/Chandra afterglow position analysis
  10. GRB 050525: RTT150, Optical observations
  11. GRB 050525a: SARA Observations
  12. GRB 050525B: Swift-BAT observations
  13. GRB 050525: MITSuME Optical Observation in VRI
  14. GRB050525A,optical observation
  15. GRB050525: Super-LOTIS observations
  16. GRB 050525, spectral lag pseudo-redshift
  17. GRB050306: optical afterglow not confirmed
  18. GRB 050525: BART optical observation
  19. GRB 050525A: BOOTES simultaneous optical observations
  20. GRB 050525A: Swift-BAT refined analysis
  21. GRB050525: Optical observations
  22. GRB 050525B: INTEGRAL shows it is unrelated to GRB050525A
  23. Konus-Wind observation of GRB 050525
  24. GRB 050525: TAROT observations of the early afterglow
  25. INTEGRAL detection of GRB 050525
  26. GRB 050525, infrared observations
  27. GRB 050525: observatons of the optical afterglow
  28. GRB050525: ROTSE-III Refined Analysis
  29. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  30. XRF050522: Radio Observations
  31. Swift/UVOT observation of XRF 050522
  32. GRB 050509A: Further I-band imaging
  33. GRB050522,optical observation
  34. GRB050520,optical observation
  35. XRF 050522: Continued NIR P200 Monitoring
  36. RBO Observations of GRB050522
  37. Recent GRB BVRcIc field photometry
  38. GRB050520: Radio Observations
  39. XRF 050522: Swift XRT observation
  40. XRF050522, BVRcIc field photometry
  41. XRF050522: Optical Observations
  42. XRF050522: Near-infrared Observations
  43. GRB 050520: VLT/ULTRACAM observations
  44. GRB 050520: Swift XRT refined analysis
  45. XRF050509C: Chandra Afterglow Detection
  46. XRF050509c: Radio Observations
  47. GRB 050520: P200 Observations
  48. GRB 050520: TAROT optical limit
  49. GRB 050520: VLT/ULTRACAM observations
  50. XRF 050509c optical afterglow
  51. GRB 050509B and short GRB-SN association? (corrected)
  52. GRB 050509B and short GRB-SN association?
  53. GRB050502b: Early Observation
  54. GRB050509b, Bok telescope B-band imaging
  55. Refined Chandra analysis of GRB 050509b
  56. GRB050509b, SDSS pre-burst observations
  57. GRB 050509b: Keck/Chandra Cross-Correlation
  58. GRB 050509b: Keck/Chandra Cross-Correlation
  59. Chandra observation of GRB 050509b
  60. GRB 050509b: RAPTOR deep, early limits.
  61. GRB050509B: Optical observations at the Very Large Telescope
  62. GRB 050509b: No Optical Variability in XRT Error Circle
  63. GRB 050509a: Swift-BAT refined analysis
  64. GRB 050509c: ROTSE-III Optical Limits
  65. GRB 050505, early TAROT observation
  66. GRB050509c: REM NIR and Optical observations
  67. GRB 050509b: Physical Properties of the Candidate Host galaxy
  68. GRB 050505: SARA Observations
  69. GRB 050509B, Optical Observations
  70. GRB 050509B: Swift/XRT refined analysis
  71. GRB 050509b: Optical observations
  72. GRB 050509A: Optical observations
  73. GRB050509b: Radio Observations
  74. GRB 050509b: PAIRITEL and WIYN Observations
  75. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  76. Swift Detection of GRB050509b: A short duration burst
  77. Swift Detection of the Burst GRB050509
  78. GRB 050505: early time observations
  79. GRB 050505, simultaneous optical observation
  80. GRB050505: AAVSO observations
  81. GRB050416A : 1 GHz limit from GMRT
  82. GRB050505: Optical Afterglow Candidate
  83. GRB050505 Swift-BAT refined analysis
  84. GRB 050416b:Swift XRT afterglow upper limits
  85. GRB 050416b:Swift XRT afterglow upper limits
  86. GRB050502b: Afterglow Confirmation: Correction to OT Coordinates
  87. GRB050502b: Afterglow Confirmation
  88. GRB050502: P200 Observations (Correction)
  89. GRB050502: P200 Observations
  90. GRB 050504 : R band observation at Lulin observatory
  91. Swift UVOT observation of GRB 050504
  92. GRB 050504, R band Observations
  93. GRB 050502b, V band Observations
  94. GRB050504: P60 Observations
  95. GRB 050504: A long GRB detected with INTEGRAL
  96. GRB (?) 050504: IR Observations, Intriguing Source
  97. GRB 050502b, Optical observations
  98. GRB050502a: P60 Observations (Correction)
  99. GRB050502a: P60 Observations
  100. Renewal of SGR 1806-20 activity

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