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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"

28047 results found.

  1. GRB 050525: MITSuME Optical Observation in VRI
  2. GRB050525A,optical observation
  3. GRB050525: Super-LOTIS observations
  4. GRB 050525, spectral lag pseudo-redshift
  5. GRB050306: optical afterglow not confirmed
  6. GRB 050525: BART optical observation
  7. GRB 050525A: BOOTES simultaneous optical observations
  8. GRB 050525A: Swift-BAT refined analysis
  9. GRB050525: Optical observations
  10. GRB 050525B: INTEGRAL shows it is unrelated to GRB050525A
  11. Konus-Wind observation of GRB 050525
  12. GRB 050525: TAROT observations of the early afterglow
  13. INTEGRAL detection of GRB 050525
  14. GRB 050525, infrared observations
  15. GRB 050525: observatons of the optical afterglow
  16. GRB050525: ROTSE-III Refined Analysis
  17. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  18. XRF050522: Radio Observations
  19. Swift/UVOT observation of XRF 050522
  20. GRB 050509A: Further I-band imaging
  21. GRB050522,optical observation
  22. GRB050520,optical observation
  23. XRF 050522: Continued NIR P200 Monitoring
  24. RBO Observations of GRB050522
  25. Recent GRB BVRcIc field photometry
  26. GRB050520: Radio Observations
  27. XRF 050522: Swift XRT observation
  28. XRF050522, BVRcIc field photometry
  29. XRF050522: Optical Observations
  30. XRF050522: Near-infrared Observations
  31. GRB 050520: VLT/ULTRACAM observations
  32. GRB 050520: Swift XRT refined analysis
  33. XRF050509C: Chandra Afterglow Detection
  34. XRF050509c: Radio Observations
  35. GRB 050520: P200 Observations
  36. GRB 050520: TAROT optical limit
  37. GRB 050520: VLT/ULTRACAM observations
  38. XRF 050509c optical afterglow
  39. GRB 050509B and short GRB-SN association? (corrected)
  40. GRB 050509B and short GRB-SN association?
  41. GRB050502b: Early Observation
  42. GRB050509b, Bok telescope B-band imaging
  43. Refined Chandra analysis of GRB 050509b
  44. GRB050509b, SDSS pre-burst observations
  45. GRB 050509b: Keck/Chandra Cross-Correlation
  46. GRB 050509b: Keck/Chandra Cross-Correlation
  47. Chandra observation of GRB 050509b
  48. GRB 050509b: RAPTOR deep, early limits.
  49. GRB050509B: Optical observations at the Very Large Telescope
  50. GRB 050509b: No Optical Variability in XRT Error Circle
  51. GRB 050509a: Swift-BAT refined analysis
  52. GRB 050509c: ROTSE-III Optical Limits
  53. GRB 050505, early TAROT observation
  54. GRB050509c: REM NIR and Optical observations
  55. GRB 050509b: Physical Properties of the Candidate Host galaxy
  56. GRB 050505: SARA Observations
  57. GRB 050509B, Optical Observations
  58. GRB 050509B: Swift/XRT refined analysis
  59. GRB 050509b: Optical observations
  60. GRB 050509A: Optical observations
  61. GRB050509b: Radio Observations
  62. GRB 050509b: PAIRITEL and WIYN Observations
  63. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  64. Swift Detection of GRB050509b: A short duration burst
  65. Swift Detection of the Burst GRB050509
  66. GRB 050505: early time observations
  67. GRB 050505, simultaneous optical observation
  68. GRB050505: AAVSO observations
  69. GRB050416A : 1 GHz limit from GMRT
  70. GRB050505: Optical Afterglow Candidate
  71. GRB050505 Swift-BAT refined analysis
  72. GRB 050416b:Swift XRT afterglow upper limits
  73. GRB 050416b:Swift XRT afterglow upper limits
  74. GRB050502b: Afterglow Confirmation: Correction to OT Coordinates
  75. GRB050502b: Afterglow Confirmation
  76. GRB050502: P200 Observations (Correction)
  77. GRB050502: P200 Observations
  78. GRB 050504 : R band observation at Lulin observatory
  79. Swift UVOT observation of GRB 050504
  80. GRB 050504, R band Observations
  81. GRB 050502b, V band Observations
  82. GRB050504: P60 Observations
  83. GRB 050504: A long GRB detected with INTEGRAL
  84. GRB (?) 050504: IR Observations, Intriguing Source
  85. GRB 050502b, Optical observations
  86. GRB050502a: P60 Observations (Correction)
  87. GRB050502a: P60 Observations
  88. Renewal of SGR 1806-20 activity
  89. GRB050502B Swift-BAT refined analysis
  90. Swift UVOT refined analysis
  91. GRB 050502a : R band observation at Lulin observatory
  92. GRB 050502b : optical observation at Lulin observatory
  93. GRB 050502A: Redshift measurement based on Keck HIRES Observations
  94. Swift Detection of the Bright Burst GRB050502b
  95. GRB 050502: INTEGRAL results
  96. GRB 050502: ROTSE-III Detection of Possible Counterpart
  97. Swift/BAT possible detection of a weak burst GRB050430
  98. GRB050416a: Radio Detection
  99. GRB 050422: Swift-UVOT observation
  100. GRB 050422: Swift-BAT refined analysis

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