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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"

20951 results found.

  1. GRB 050607: Optical decay and spectral slope
  2. GRB 050607: MDM Observations
  3. GRB 050607 - XRT refined data analysis
  4. Optical Afterglow of GRB 050607
  5. GRB050607: P60 Observations
  6. GRB050607: prompt REM observations
  7. GRB 050603: prediction of t_break
  8. GRB 050603: Redshift
  9. GRB 050603 - XRT data analysis of the first day
  10. GRB 050603: Analysis of UVOT data
  11. GRB050603: Fading Afterglow observed by Swift UVOT
  12. GRB050603, submillimetre observations
  13. GRB 050603: Swift XRT Position
  14. GRB 050603: Swift-BAT refined analysis of a long three-spiked burst
  15. Swift/BAT Detection of GRB050603
  16. GRB 050408: jet break in the XRT light curve
  17. GRB 050525a, infrared observations
  18. GRB 050525a, SMARTS optical/IR afterglow observations
  19. GRB050528, XRT observations
  20. GRB050528: updated Liverpool Telescope limits
  21. Possible GRB050528: no candidate from Liverpool Telescope
  22. GRB050525a: Radio Observations
  23. GRB 050525: RTT150, Optical observations
  24. GRB 050525a: SARA Observations
  25. GRB 050525B: Swift-BAT observations
  26. GRB 050525a: MDM Observations
  27. GRB 050525 : Lulin optical afterglow observations
  28. GRB050525: Super-LOTIS observations
  29. GRB050306: optical afterglow not confirmed
  30. GRB 050525A: BOOTES simultaneous optical observations
  31. GRB050525: Optical observations
  32. GRB 050525: TAROT observations of the early afterglow
  33. GRB 050525, infrared observations
  34. GRB 050525: observatons of the optical afterglow
  35. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  36. GRB 050525A: ROTSE-III Detection of Possible Counterpart
  37. XRF050522: NIR observations of XRT candidate
  38. XRF 050522: Swift XRT refined analysis
  39. XRF050522: Radio Observations
  40. XRF 050522: Continued NIR P200 Monitoring
  41. RBO Observations of GRB050522
  42. GRB050509b: optical observations
  43. GRB050520: Radio Observations
  44. XRF 050522: Swift XRT observation
  45. XRF050522, BVRcIc field photometry
  46. XRF 050522 : Lulin observations
  47. XRF050522: Optical Observations
  48. XRF050522: Near-infrared Observations
  49. XRF 050522: KAIT observations
  50. GRB 050520: VLT/ULTRACAM observations
  51. Swift UVOT Observations of GRB 050520
  52. XRF 050509c: Swift XRT Upper Limit
  53. XRF050509c: Radio Observations
  54. RBO Observations of GRB050520
  55. GRB 050520: P200 Observations
  56. RBO Observations of GRB050520
  57. GRB 050520: TAROT optical limit
  58. GRB 050520: Swift XRT position
  59. GRB 050520: VLT/ULTRACAM observations
  60. GRB 050520: OSN optical observations
  61. GRB 050504: Swift XRT afterglow candidate has faded
  62. XRF 050509c optical afterglow
  63. GRB 050509B: Subaru Optical Observations
  64. GRB050509b, SDSS pre-burst observations
  65. GRB 050509b: Keck/Chandra Cross-Correlation
  66. Chandra observation of GRB 050509b
  67. GRB050509B: Optical/Infared observations
  68. GRB 050509b Milagro GeV/TeV Observations
  69. GRB050509B: Optical observations at the Very Large Telescope
  70. GRB 050509b: No Optical Variability in XRT Error Circle
  71. GRB 050509B: WSRT Radio Observations
  72. GRB050509c: REM NIR and Optical observations (errata corrige to GCN 3400)
  73. GRB 050505, early TAROT observation
  74. GRB050509c: REM NIR and Optical observations
  75. GRB 050505: SARA Observations
  76. Swift UVOT Follow-up Observations of GRB 050509B
  77. GRB 050509B, Optical Observations
  78. GRB050509a: Swift UVOT observations
  79. GRB 050509b: Optical observations
  80. GRB 050509b: Possible Optical Counterpart
  81. GRB 050509A: Optical observations
  82. GRB 050509b: Optical Counterpart Candidate
  83. GRB050509b: Radio Observations
  84. GRB 050509b: PAIRITEL and WIYN Observations
  85. GRB 050509b: optical observations
  86. GRB 050509b: Swift XRT Position
  87. Swift Detection of GRB050509b: A short duration burst
  88. Swift Detection of the Burst GRB050509
  89. GRB 050505: early time observations
  90. GRB 050505 - Faulkes Telescope North observations
  91. GRB 050502a: Swift XRT Upper Limit
  92. GRB050505: Infrared observations
  93. GRB 050505: Further Swift UVOT observations.
  94. GRB050505: AAVSO observations
  95. GRB 050505 UVOT
  96. GRB050505: Optical Afterglow Candidate
  97. GRB050505 Swift-BAT refined analysis
  98. GRB 050502a: Optical Observations
  99. GRB 050416b:Swift XRT afterglow upper limits
  100. GRB 050416b:Swift XRT afterglow upper limits

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