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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"

27481 results found.

  1. GRB050701: Swift-BAT Refined analysis
  2. Swift trigger 143708 is really GRB 050701
  3. GRB 050607, radio observations
  4. H11603: An X-ray flare from V4641 Sgr, or a possible XRF
  5. GRB050525a: HST Observations
  6. H3800 and H3801 on 2005 June 11: two bursts from SGR1806-20 localized by HETE
  7. XRF 050509c: Optical monitoring
  8. Konus-Wind observation of an intermediate burst from SGR 1806-20
  9. XRF050509c: Radio Detection
  10. GRB 050607 optical decay
  11. GRB050607: refined analysis of prompt REM observations
  12. GRB 050607: PROMPT VRcIc Observations
  13. GRB 050607: Optical decay and spectral slope
  14. GRB050607,optical observation
  15. Optical Afterglow of GRB 050607
  16. GRB050607: Swift Detection of a long GRB
  17. GRB050607: prompt REM observations
  18. Limits on a SN in the field of GRB 050509b
  19. GRB 050603 - XRT data analysis of the first day
  20. GRB050603, submillimetre observations
  21. GRB050603: Radio Detection
  22. GRB 050603: Swift-BAT refined analysis of a long three-spiked burst
  23. GRB 050603: INTEGRAL shows it is not a short GRB
  24. GRB 050525a, infrared observations
  25. GRB050528, XRT observations
  26. GRB050528: updated Liverpool Telescope limits
  27. Swift-BAT GRB 050528: a soft burst
  28. GRB050504: Ashra-P2/3 monitor and Ashra-AFT response
  29. Possible GRB050528: no candidate from Liverpool Telescope
  30. GRB050525a: Radio Observations
  31. GRB 050509b: refined XRT/Chandra afterglow position analysis
  32. GRB 050525: RTT150, Optical observations
  33. GRB 050525a: SARA Observations
  34. GRB 050525B: Swift-BAT observations
  35. GRB 050525: MITSuME Optical Observation in VRI
  36. GRB050525A,optical observation
  37. GRB050525: Super-LOTIS observations
  38. GRB 050525, spectral lag pseudo-redshift
  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. GRB 050525B: INTEGRAL shows it is unrelated to GRB050525A
  45. Konus-Wind observation of GRB 050525
  46. GRB 050525: TAROT observations of the early afterglow
  47. INTEGRAL detection of GRB 050525
  48. GRB 050525, infrared observations
  49. GRB 050525: observatons of the optical afterglow
  50. GRB050525: ROTSE-III Refined Analysis
  51. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  52. XRF050522: Radio Observations
  53. Swift/UVOT observation of XRF 050522
  54. GRB 050509A: Further I-band imaging
  55. GRB050522,optical observation
  56. GRB050520,optical observation
  57. XRF 050522: Continued NIR P200 Monitoring
  58. RBO Observations of GRB050522
  59. Recent GRB BVRcIc field photometry
  60. GRB050520: Radio Observations
  61. XRF 050522: Swift XRT observation
  62. XRF050522, BVRcIc field photometry
  63. XRF050522: Optical Observations
  64. XRF050522: Near-infrared Observations
  65. GRB 050520: VLT/ULTRACAM observations
  66. GRB 050520: Swift XRT refined analysis
  67. XRF050509C: Chandra Afterglow Detection
  68. XRF050509c: Radio Observations
  69. GRB 050520: P200 Observations
  70. GRB 050520: TAROT optical limit
  71. GRB 050520: VLT/ULTRACAM observations
  72. XRF 050509c optical afterglow
  73. GRB 050509B and short GRB-SN association? (corrected)
  74. GRB 050509B and short GRB-SN association?
  75. GRB050502b: Early Observation
  76. GRB050509b, Bok telescope B-band imaging
  77. Refined Chandra analysis of GRB 050509b
  78. GRB050509b, SDSS pre-burst observations
  79. GRB 050509b: Keck/Chandra Cross-Correlation
  80. GRB 050509b: Keck/Chandra Cross-Correlation
  81. Chandra observation of GRB 050509b
  82. GRB 050509b: RAPTOR deep, early limits.
  83. GRB050509B: Optical observations at the Very Large Telescope
  84. GRB 050509b: No Optical Variability in XRT Error Circle
  85. GRB 050509a: Swift-BAT refined analysis
  86. GRB 050509c: ROTSE-III Optical Limits
  87. GRB 050505, early TAROT observation
  88. GRB050509c: REM NIR and Optical observations
  89. GRB 050509b: Physical Properties of the Candidate Host galaxy
  90. GRB 050505: SARA Observations
  91. GRB 050509B, Optical Observations
  92. GRB 050509B: Swift/XRT refined analysis
  93. GRB 050509b: Optical observations
  94. GRB 050509A: Optical observations
  95. GRB050509b: Radio Observations
  96. GRB 050509b: PAIRITEL and WIYN Observations
  97. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  98. Swift Detection of GRB050509b: A short duration burst
  99. Swift Detection of the Burst GRB050509
  100. GRB 050505: early time observations

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