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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"

15986 results found.

  1. GRB 050607, radio observations
  2. H11603: An X-ray flare from V4641 Sgr, or a possible XRF
  3. GRB 050525A: Swift Late-Time Decay Rate
  4. H3804: A Possible New XRB Detected by HETE
  5. H3800 and H3801 on 2005 June 11: two bursts from SGR1806-20 localized by HETE
  6. XRF 050509c: Optical monitoring
  7. XRF050509c: Radio Detection
  8. GRB 050607 optical decay
  9. GRB 050607: RTT150 optical observations
  10. GRB050607: refined analysis of prompt REM observations
  11. Swift/UVOT observations of GRB050607
  12. GRB 050607: RAPTOR-S Early Optical Limits
  13. GRB050607: KAIT optical limits
  14. GRB 050525a, Mid-Infrared Observations
  15. GRB 050607: Optical decay and spectral slope
  16. GRB 050607: MDM Observations
  17. GRB050607,optical observation
  18. GRB 050607 - XRT refined data analysis
  19. Optical Afterglow of GRB 050607
  20. GRB050607 optical limit by "Pi of the Sky"
  21. GRB050607: prompt REM observations
  22. GRB050603: Fading Afterglow observed by Swift UVOT
  23. GRB 050603: Swift XRT Position
  24. GRB050603: Radio Detection
  25. GRB 050525a, SMARTS optical/IR afterglow observations
  26. GRB050528: BOOTES optical candidate (retraction)
  27. GRB050528: BOOTES optical candidate
  28. GRB050525a: Radio Observations
  29. GRB 050525: RTT150, Optical observations
  30. GRB050525a: optical upper limits
  31. GRB 050525a: SARA Observations
  32. GRB 050525: MITSuME Optical Observation in VRI
  33. GRB 050525a: MDM Observations
  34. GRB050525A,optical observation
  35. GRB 050525 : Lulin optical afterglow observations
  36. GRB050525: Super-LOTIS observations
  37. GRB 050525a: Gemini/GMOS Spectra
  38. GRB050306: optical afterglow not confirmed
  39. GRB 050525: BART optical observation
  40. GRB 050525A: BOOTES simultaneous optical observations
  41. GRB 050525A: Swift-BAT refined analysis
  42. GRB050525: Optical observations
  43. Swift/UVOT UV and optical detections of GRB 050525
  44. GRB 050525, infrared observations
  45. GRB 050525: Optical observation
  46. GRB 050525: observatons of the optical afterglow
  47. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  48. GRB 050509A: Further I-band imaging
  49. GRB050522,optical observation
  50. GRB050520,optical observation
  51. GRB050509b: optical observations
  52. Recent GRB BVRcIc field photometry
  53. XRF050522: Optical Observations
  54. XRF 050522 detected with INTEGRAL
  55. Swift UVOT Observations of GRB 050520
  56. XRF 050509c: Swift XRT Upper Limit
  57. GRB 050520: TAROT optical limit
  58. GRB 050520: OSN optical observations
  59. GRB 050520: BART optical limit
  60. GRB 050520 - A long GRB detected with INTEGRAL
  61. XRF 050509C: REM NIR and Optical refined analysis
  62. XRF 050509c optical afterglow
  63. GRB 050509B and short GRB-SN association? (corrected)
  64. GRB 050509B and short GRB-SN association?
  65. GRB 050509B: Subaru Optical Observations
  66. GRB050502b: Early Observation
  67. GRB050509B: Optical/Infared observations
  68. GRB 050509b: Swift/UVOT follow-up measurements
  69. GRB050509B: Optical observations at the Very Large Telescope
  70. GRB 050509b: No Optical Variability in XRT Error Circle
  71. GRB050416: Afterglow detection at 188 nm with Swift UVOT
  72. GRB 050509c: ROTSE-III Optical Limits
  73. GRB 050509B: WSRT Radio Observations
  74. GRB050509c: REM NIR and Optical observations (errata corrige to GCN 3400)
  75. GRB050509c (=H3751): An X-Ray Flash Localized By HETE
  76. GRB 050509b: Further Analysis of Keck LRIS Images
  77. GRB050509c: REM NIR and Optical observations
  78. GRB 050505: SARA Observations
  79. Swift UVOT Follow-up Observations of GRB 050509B
  80. GRB 050509B, Optical Observations
  81. GRB050509a: Swift UVOT observations
  82. GRB 050509b: Optical observations
  83. GRB 050509b: Possible Optical Counterpart
  84. GRB 050509A: Optical observations
  85. GRB 050509b: Optical Counterpart Candidate
  86. GRB 050509b: optical observations
  87. GRB 050509b: Swift XRT Position
  88. GRB 050509B: ROTSE-III Optical Limits
  89. Swift Detection of GRB050509b: A short duration burst
  90. Swift Detection of the Burst GRB050509
  91. GRB 050505: early time observations
  92. GRB 050505 - Faulkes Telescope North observations
  93. GRB 050502a: Swift XRT Upper Limit
  94. GRB 050505, simultaneous optical observation
  95. GRB050505: Infrared observations
  96. GRB 050505: Further Swift UVOT observations.
  97. GRB050505: AAVSO observations
  98. GRB 050505: Keck absorption spectrum and redshift (z=4.27)
  99. GRB 050505 UVOT
  100. GRB050505: Optical Afterglow Candidate

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