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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"

28057 results found.

  1. GRB050528, XRT observations
  2. GRB050528: updated Liverpool Telescope limits
  3. Swift-BAT GRB 050528: a soft burst
  4. GRB050504: Ashra-P2/3 monitor and Ashra-AFT response
  5. Possible GRB050528: no candidate from Liverpool Telescope
  6. GRB050525a: Radio Observations
  7. GRB 050509b: refined XRT/Chandra afterglow position analysis
  8. GRB 050525: RTT150, Optical observations
  9. GRB 050525a: SARA Observations
  10. GRB 050525B: Swift-BAT observations
  11. GRB 050525: MITSuME Optical Observation in VRI
  12. GRB050525A,optical observation
  13. GRB050525: Super-LOTIS observations
  14. GRB 050525, spectral lag pseudo-redshift
  15. GRB050306: optical afterglow not confirmed
  16. GRB 050525: BART optical observation
  17. GRB 050525A: BOOTES simultaneous optical observations
  18. GRB 050525A: Swift-BAT refined analysis
  19. GRB050525: Optical observations
  20. GRB 050525B: INTEGRAL shows it is unrelated to GRB050525A
  21. Konus-Wind observation of GRB 050525
  22. GRB 050525: TAROT observations of the early afterglow
  23. INTEGRAL detection of GRB 050525
  24. GRB 050525, infrared observations
  25. GRB 050525: observatons of the optical afterglow
  26. GRB050525: ROTSE-III Refined Analysis
  27. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  28. XRF050522: Radio Observations
  29. Swift/UVOT observation of XRF 050522
  30. GRB 050509A: Further I-band imaging
  31. GRB050522,optical observation
  32. GRB050520,optical observation
  33. XRF 050522: Continued NIR P200 Monitoring
  34. RBO Observations of GRB050522
  35. Recent GRB BVRcIc field photometry
  36. GRB050520: Radio Observations
  37. XRF 050522: Swift XRT observation
  38. XRF050522, BVRcIc field photometry
  39. XRF050522: Optical Observations
  40. XRF050522: Near-infrared Observations
  41. GRB 050520: VLT/ULTRACAM observations
  42. GRB 050520: Swift XRT refined analysis
  43. XRF050509C: Chandra Afterglow Detection
  44. XRF050509c: Radio Observations
  45. GRB 050520: P200 Observations
  46. GRB 050520: TAROT optical limit
  47. GRB 050520: VLT/ULTRACAM observations
  48. XRF 050509c optical afterglow
  49. GRB 050509B and short GRB-SN association? (corrected)
  50. GRB 050509B and short GRB-SN association?
  51. GRB050502b: Early Observation
  52. GRB050509b, Bok telescope B-band imaging
  53. Refined Chandra analysis of GRB 050509b
  54. GRB050509b, SDSS pre-burst observations
  55. GRB 050509b: Keck/Chandra Cross-Correlation
  56. GRB 050509b: Keck/Chandra Cross-Correlation
  57. Chandra observation of GRB 050509b
  58. GRB 050509b: RAPTOR deep, early limits.
  59. GRB050509B: Optical observations at the Very Large Telescope
  60. GRB 050509b: No Optical Variability in XRT Error Circle
  61. GRB 050509a: Swift-BAT refined analysis
  62. GRB 050509c: ROTSE-III Optical Limits
  63. GRB 050505, early TAROT observation
  64. GRB050509c: REM NIR and Optical observations
  65. GRB 050509b: Physical Properties of the Candidate Host galaxy
  66. GRB 050505: SARA Observations
  67. GRB 050509B, Optical Observations
  68. GRB 050509B: Swift/XRT refined analysis
  69. GRB 050509b: Optical observations
  70. GRB 050509A: Optical observations
  71. GRB050509b: Radio Observations
  72. GRB 050509b: PAIRITEL and WIYN Observations
  73. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  74. Swift Detection of GRB050509b: A short duration burst
  75. Swift Detection of the Burst GRB050509
  76. GRB 050505: early time observations
  77. GRB 050505, simultaneous optical observation
  78. GRB050505: AAVSO observations
  79. GRB050416A : 1 GHz limit from GMRT
  80. GRB050505: Optical Afterglow Candidate
  81. GRB050505 Swift-BAT refined analysis
  82. GRB 050416b:Swift XRT afterglow upper limits
  83. GRB 050416b:Swift XRT afterglow upper limits
  84. GRB050502b: Afterglow Confirmation: Correction to OT Coordinates
  85. GRB050502b: Afterglow Confirmation
  86. GRB050502: P200 Observations (Correction)
  87. GRB050502: P200 Observations
  88. GRB 050504 : R band observation at Lulin observatory
  89. Swift UVOT observation of GRB 050504
  90. GRB 050504, R band Observations
  91. GRB 050502b, V band Observations
  92. GRB050504: P60 Observations
  93. GRB 050504: A long GRB detected with INTEGRAL
  94. GRB (?) 050504: IR Observations, Intriguing Source
  95. GRB 050502b, Optical observations
  96. GRB050502a: P60 Observations (Correction)
  97. GRB050502a: P60 Observations
  98. Renewal of SGR 1806-20 activity
  99. GRB050502B Swift-BAT refined analysis
  100. Swift UVOT refined analysis

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