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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"

26360 results found.

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

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