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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"

15987 results found.

  1. GRB 050701, optical observations
  2. GRB 050607, radio observations
  3. H11603: An X-ray flare from V4641 Sgr, or a possible XRF
  4. GRB 050525A: Swift Late-Time Decay Rate
  5. H3804: A Possible New XRB Detected by HETE
  6. H3800 and H3801 on 2005 June 11: two bursts from SGR1806-20 localized by HETE
  7. XRF 050509c: Optical monitoring
  8. XRF050509c: Radio Detection
  9. GRB 050607 optical decay
  10. GRB 050607: RTT150 optical observations
  11. GRB050607: refined analysis of prompt REM observations
  12. Swift/UVOT observations of GRB050607
  13. GRB 050607: RAPTOR-S Early Optical Limits
  14. GRB050607: KAIT optical limits
  15. GRB 050525a, Mid-Infrared Observations
  16. GRB 050607: Optical decay and spectral slope
  17. GRB 050607: MDM Observations
  18. GRB050607,optical observation
  19. GRB 050607 - XRT refined data analysis
  20. Optical Afterglow of GRB 050607
  21. GRB050607 optical limit by "Pi of the Sky"
  22. GRB050607: prompt REM observations
  23. GRB050603: Fading Afterglow observed by Swift UVOT
  24. GRB 050603: Swift XRT Position
  25. GRB050603: Radio Detection
  26. GRB 050525a, SMARTS optical/IR afterglow observations
  27. GRB050528: BOOTES optical candidate (retraction)
  28. GRB050528: BOOTES optical candidate
  29. GRB050525a: Radio Observations
  30. GRB 050525: RTT150, Optical observations
  31. GRB050525a: optical upper limits
  32. GRB 050525a: SARA Observations
  33. GRB 050525: MITSuME Optical Observation in VRI
  34. GRB 050525a: MDM Observations
  35. GRB050525A,optical observation
  36. GRB 050525 : Lulin optical afterglow observations
  37. GRB050525: Super-LOTIS observations
  38. GRB 050525a: Gemini/GMOS Spectra
  39. GRB050306: optical afterglow not confirmed
  40. GRB 050525: BART optical observation
  41. GRB 050525A: BOOTES simultaneous optical observations
  42. GRB 050525A: Swift-BAT refined analysis
  43. GRB050525: Optical observations
  44. Swift/UVOT UV and optical detections of GRB 050525
  45. GRB 050525, infrared observations
  46. GRB 050525: Optical observation
  47. GRB 050525: observatons of the optical afterglow
  48. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  49. GRB 050509A: Further I-band imaging
  50. GRB050522,optical observation
  51. GRB050520,optical observation
  52. GRB050509b: optical observations
  53. Recent GRB BVRcIc field photometry
  54. XRF050522: Optical Observations
  55. XRF 050522 detected with INTEGRAL
  56. Swift UVOT Observations of GRB 050520
  57. XRF 050509c: Swift XRT Upper Limit
  58. GRB 050520: TAROT optical limit
  59. GRB 050520: OSN optical observations
  60. GRB 050520: BART optical limit
  61. GRB 050520 - A long GRB detected with INTEGRAL
  62. XRF 050509C: REM NIR and Optical refined analysis
  63. XRF 050509c optical afterglow
  64. GRB 050509B and short GRB-SN association? (corrected)
  65. GRB 050509B and short GRB-SN association?
  66. GRB 050509B: Subaru Optical Observations
  67. GRB050502b: Early Observation
  68. GRB050509B: Optical/Infared observations
  69. GRB 050509b: Swift/UVOT follow-up measurements
  70. GRB050509B: Optical observations at the Very Large Telescope
  71. GRB 050509b: No Optical Variability in XRT Error Circle
  72. GRB050416: Afterglow detection at 188 nm with Swift UVOT
  73. GRB 050509c: ROTSE-III Optical Limits
  74. GRB 050509B: WSRT Radio Observations
  75. GRB050509c: REM NIR and Optical observations (errata corrige to GCN 3400)
  76. GRB050509c (=H3751): An X-Ray Flash Localized By HETE
  77. GRB 050509b: Further Analysis of Keck LRIS Images
  78. GRB050509c: REM NIR and Optical observations
  79. GRB 050505: SARA Observations
  80. Swift UVOT Follow-up Observations of GRB 050509B
  81. GRB 050509B, Optical Observations
  82. GRB050509a: Swift UVOT observations
  83. GRB 050509b: Optical observations
  84. GRB 050509b: Possible Optical Counterpart
  85. GRB 050509A: Optical observations
  86. GRB 050509b: Optical Counterpart Candidate
  87. GRB 050509b: optical observations
  88. GRB 050509b: Swift XRT Position
  89. GRB 050509B: ROTSE-III Optical Limits
  90. Swift Detection of GRB050509b: A short duration burst
  91. Swift Detection of the Burst GRB050509
  92. GRB 050505: early time observations
  93. GRB 050505 - Faulkes Telescope North observations
  94. GRB 050502a: Swift XRT Upper Limit
  95. GRB 050505, simultaneous optical observation
  96. GRB050505: Infrared observations
  97. GRB 050505: Further Swift UVOT observations.
  98. GRB050505: AAVSO observations
  99. GRB 050505: Keck absorption spectrum and redshift (z=4.27)
  100. GRB 050505 UVOT

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