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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"

26363 results found.

  1. GRB 050603 - XRT data analysis of the first day
  2. GRB050603, submillimetre observations
  3. GRB050603: Radio Detection
  4. GRB 050603: Swift-BAT refined analysis of a long three-spiked burst
  5. GRB 050603: INTEGRAL shows it is not a short GRB
  6. GRB 050525a, infrared observations
  7. GRB050528, XRT observations
  8. GRB050528: updated Liverpool Telescope limits
  9. Swift-BAT GRB 050528: a soft burst
  10. GRB050504: Ashra-P2/3 monitor and Ashra-AFT response
  11. Possible GRB050528: no candidate from Liverpool Telescope
  12. GRB050525a: Radio Observations
  13. GRB 050509b: refined XRT/Chandra afterglow position analysis
  14. GRB 050525: RTT150, Optical observations
  15. GRB 050525a: SARA Observations
  16. GRB 050525B: Swift-BAT observations
  17. GRB 050525: MITSuME Optical Observation in VRI
  18. GRB050525A,optical observation
  19. GRB050525: Super-LOTIS observations
  20. GRB 050525, spectral lag pseudo-redshift
  21. GRB050306: optical afterglow not confirmed
  22. GRB 050525: BART optical observation
  23. GRB 050525A: BOOTES simultaneous optical observations
  24. GRB 050525A: Swift-BAT refined analysis
  25. GRB050525: Optical observations
  26. GRB 050525B: INTEGRAL shows it is unrelated to GRB050525A
  27. Konus-Wind observation of GRB 050525
  28. GRB 050525: TAROT observations of the early afterglow
  29. INTEGRAL detection of GRB 050525
  30. GRB 050525, infrared observations
  31. GRB 050525: observatons of the optical afterglow
  32. GRB050525: ROTSE-III Refined Analysis
  33. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  34. XRF050522: Radio Observations
  35. Swift/UVOT observation of XRF 050522
  36. GRB 050509A: Further I-band imaging
  37. GRB050522,optical observation
  38. GRB050520,optical observation
  39. XRF 050522: Continued NIR P200 Monitoring
  40. RBO Observations of GRB050522
  41. Recent GRB BVRcIc field photometry
  42. GRB050520: Radio Observations
  43. XRF 050522: Swift XRT observation
  44. XRF050522, BVRcIc field photometry
  45. XRF050522: Optical Observations
  46. XRF050522: Near-infrared Observations
  47. GRB 050520: VLT/ULTRACAM observations
  48. GRB 050520: Swift XRT refined analysis
  49. XRF050509C: Chandra Afterglow Detection
  50. XRF050509c: Radio Observations
  51. GRB 050520: P200 Observations
  52. GRB 050520: TAROT optical limit
  53. GRB 050520: VLT/ULTRACAM observations
  54. XRF 050509c optical afterglow
  55. GRB 050509B and short GRB-SN association? (corrected)
  56. GRB 050509B and short GRB-SN association?
  57. GRB050502b: Early Observation
  58. GRB050509b, Bok telescope B-band imaging
  59. Refined Chandra analysis of GRB 050509b
  60. GRB050509b, SDSS pre-burst observations
  61. GRB 050509b: Keck/Chandra Cross-Correlation
  62. GRB 050509b: Keck/Chandra Cross-Correlation
  63. Chandra observation of GRB 050509b
  64. GRB 050509b: RAPTOR deep, early limits.
  65. GRB050509B: Optical observations at the Very Large Telescope
  66. GRB 050509b: No Optical Variability in XRT Error Circle
  67. GRB 050509a: Swift-BAT refined analysis
  68. GRB 050509c: ROTSE-III Optical Limits
  69. GRB 050505, early TAROT observation
  70. GRB050509c: REM NIR and Optical observations
  71. GRB 050509b: Physical Properties of the Candidate Host galaxy
  72. GRB 050505: SARA Observations
  73. GRB 050509B, Optical Observations
  74. GRB 050509B: Swift/XRT refined analysis
  75. GRB 050509b: Optical observations
  76. GRB 050509A: Optical observations
  77. GRB050509b: Radio Observations
  78. GRB 050509b: PAIRITEL and WIYN Observations
  79. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  80. Swift Detection of GRB050509b: A short duration burst
  81. Swift Detection of the Burst GRB050509
  82. GRB 050505: early time observations
  83. GRB 050505, simultaneous optical observation
  84. GRB050505: AAVSO observations
  85. GRB050416A : 1 GHz limit from GMRT
  86. GRB050505: Optical Afterglow Candidate
  87. GRB050505 Swift-BAT refined analysis
  88. GRB 050416b:Swift XRT afterglow upper limits
  89. GRB 050416b:Swift XRT afterglow upper limits
  90. GRB050502b: Afterglow Confirmation: Correction to OT Coordinates
  91. GRB050502b: Afterglow Confirmation
  92. GRB050502: P200 Observations (Correction)
  93. GRB050502: P200 Observations
  94. GRB 050504 : R band observation at Lulin observatory
  95. Swift UVOT observation of GRB 050504
  96. GRB 050504, R band Observations
  97. GRB 050502b, V band Observations
  98. GRB050504: P60 Observations
  99. GRB 050504: A long GRB detected with INTEGRAL
  100. GRB (?) 050504: IR Observations, Intriguing Source

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