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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"

26366 results found.

  1. GRB050607: Swift Detection of a long GRB
  2. GRB050607: prompt REM observations
  3. Limits on a SN in the field of GRB 050509b
  4. GRB 050603 - XRT data analysis of the first day
  5. GRB050603, submillimetre observations
  6. GRB050603: Radio Detection
  7. GRB 050603: Swift-BAT refined analysis of a long three-spiked burst
  8. GRB 050603: INTEGRAL shows it is not a short GRB
  9. GRB 050525a, infrared observations
  10. GRB050528, XRT observations
  11. GRB050528: updated Liverpool Telescope limits
  12. Swift-BAT GRB 050528: a soft burst
  13. GRB050504: Ashra-P2/3 monitor and Ashra-AFT response
  14. Possible GRB050528: no candidate from Liverpool Telescope
  15. GRB050525a: Radio Observations
  16. GRB 050509b: refined XRT/Chandra afterglow position analysis
  17. GRB 050525: RTT150, Optical observations
  18. GRB 050525a: SARA Observations
  19. GRB 050525B: Swift-BAT observations
  20. GRB 050525: MITSuME Optical Observation in VRI
  21. GRB050525A,optical observation
  22. GRB050525: Super-LOTIS observations
  23. GRB 050525, spectral lag pseudo-redshift
  24. GRB050306: optical afterglow not confirmed
  25. GRB 050525: BART optical observation
  26. GRB 050525A: BOOTES simultaneous optical observations
  27. GRB 050525A: Swift-BAT refined analysis
  28. GRB050525: Optical observations
  29. GRB 050525B: INTEGRAL shows it is unrelated to GRB050525A
  30. Konus-Wind observation of GRB 050525
  31. GRB 050525: TAROT observations of the early afterglow
  32. INTEGRAL detection of GRB 050525
  33. GRB 050525, infrared observations
  34. GRB 050525: observatons of the optical afterglow
  35. GRB050525: ROTSE-III Refined Analysis
  36. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  37. XRF050522: Radio Observations
  38. Swift/UVOT observation of XRF 050522
  39. GRB 050509A: Further I-band imaging
  40. GRB050522,optical observation
  41. GRB050520,optical observation
  42. XRF 050522: Continued NIR P200 Monitoring
  43. RBO Observations of GRB050522
  44. Recent GRB BVRcIc field photometry
  45. GRB050520: Radio Observations
  46. XRF 050522: Swift XRT observation
  47. XRF050522, BVRcIc field photometry
  48. XRF050522: Optical Observations
  49. XRF050522: Near-infrared Observations
  50. GRB 050520: VLT/ULTRACAM observations
  51. GRB 050520: Swift XRT refined analysis
  52. XRF050509C: Chandra Afterglow Detection
  53. XRF050509c: Radio Observations
  54. GRB 050520: P200 Observations
  55. GRB 050520: TAROT optical limit
  56. GRB 050520: VLT/ULTRACAM observations
  57. XRF 050509c optical afterglow
  58. GRB 050509B and short GRB-SN association? (corrected)
  59. GRB 050509B and short GRB-SN association?
  60. GRB050502b: Early Observation
  61. GRB050509b, Bok telescope B-band imaging
  62. Refined Chandra analysis of GRB 050509b
  63. GRB050509b, SDSS pre-burst observations
  64. GRB 050509b: Keck/Chandra Cross-Correlation
  65. GRB 050509b: Keck/Chandra Cross-Correlation
  66. Chandra observation of GRB 050509b
  67. GRB 050509b: RAPTOR deep, early limits.
  68. GRB050509B: Optical observations at the Very Large Telescope
  69. GRB 050509b: No Optical Variability in XRT Error Circle
  70. GRB 050509a: Swift-BAT refined analysis
  71. GRB 050509c: ROTSE-III Optical Limits
  72. GRB 050505, early TAROT observation
  73. GRB050509c: REM NIR and Optical observations
  74. GRB 050509b: Physical Properties of the Candidate Host galaxy
  75. GRB 050505: SARA Observations
  76. GRB 050509B, Optical Observations
  77. GRB 050509B: Swift/XRT refined analysis
  78. GRB 050509b: Optical observations
  79. GRB 050509A: Optical observations
  80. GRB050509b: Radio Observations
  81. GRB 050509b: PAIRITEL and WIYN Observations
  82. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  83. Swift Detection of GRB050509b: A short duration burst
  84. Swift Detection of the Burst GRB050509
  85. GRB 050505: early time observations
  86. GRB 050505, simultaneous optical observation
  87. GRB050505: AAVSO observations
  88. GRB050416A : 1 GHz limit from GMRT
  89. GRB050505: Optical Afterglow Candidate
  90. GRB050505 Swift-BAT refined analysis
  91. GRB 050416b:Swift XRT afterglow upper limits
  92. GRB 050416b:Swift XRT afterglow upper limits
  93. GRB050502b: Afterglow Confirmation: Correction to OT Coordinates
  94. GRB050502b: Afterglow Confirmation
  95. GRB050502: P200 Observations (Correction)
  96. GRB050502: P200 Observations
  97. GRB 050504 : R band observation at Lulin observatory
  98. Swift UVOT observation of GRB 050504
  99. GRB 050504, R band Observations
  100. GRB 050502b, V band Observations

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