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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').
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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"

28087 results found.

  1. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  2. GRB 050525a: ARC 3.5-Meter SPIcam Field Calibration
  3. GRB 050626: Swift XRT observations
  4. GRB 050408: ARC 3.5-meter NIR Observations
  5. GRB 050701: Refined XRT analysis
  6. Swift UVOT observations of GRB 050701
  7. GRB050701: Swift-BAT Refined analysis
  8. Swift trigger 143708 is really GRB 050701
  9. GRB 050607, radio observations
  10. H11603: An X-ray flare from V4641 Sgr, or a possible XRF
  11. GRB050525a: HST Observations
  12. H3800 and H3801 on 2005 June 11: two bursts from SGR1806-20 localized by HETE
  13. XRF 050509c: Optical monitoring
  14. Konus-Wind observation of an intermediate burst from SGR 1806-20
  15. XRF050509c: Radio Detection
  16. GRB 050607 optical decay
  17. GRB050607: refined analysis of prompt REM observations
  18. GRB 050607: PROMPT VRcIc Observations
  19. GRB 050607: Optical decay and spectral slope
  20. GRB050607,optical observation
  21. Optical Afterglow of GRB 050607
  22. GRB050607: Swift Detection of a long GRB
  23. GRB050607: prompt REM observations
  24. Limits on a SN in the field of GRB 050509b
  25. GRB 050603 - XRT data analysis of the first day
  26. GRB050603, submillimetre observations
  27. GRB050603: Radio Detection
  28. GRB 050603: Swift-BAT refined analysis of a long three-spiked burst
  29. GRB 050603: INTEGRAL shows it is not a short GRB
  30. GRB 050525a, infrared observations
  31. GRB050528, XRT observations
  32. GRB050528: updated Liverpool Telescope limits
  33. Swift-BAT GRB 050528: a soft burst
  34. GRB050504: Ashra-P2/3 monitor and Ashra-AFT response
  35. Possible GRB050528: no candidate from Liverpool Telescope
  36. GRB050525a: Radio Observations
  37. GRB 050509b: refined XRT/Chandra afterglow position analysis
  38. GRB 050525: RTT150, Optical observations
  39. GRB 050525a: SARA Observations
  40. GRB 050525B: Swift-BAT observations
  41. GRB 050525: MITSuME Optical Observation in VRI
  42. GRB050525A,optical observation
  43. GRB050525: Super-LOTIS observations
  44. GRB 050525, spectral lag pseudo-redshift
  45. GRB050306: optical afterglow not confirmed
  46. GRB 050525: BART optical observation
  47. GRB 050525A: BOOTES simultaneous optical observations
  48. GRB 050525A: Swift-BAT refined analysis
  49. GRB050525: Optical observations
  50. GRB 050525B: INTEGRAL shows it is unrelated to GRB050525A
  51. Konus-Wind observation of GRB 050525
  52. GRB 050525: TAROT observations of the early afterglow
  53. INTEGRAL detection of GRB 050525
  54. GRB 050525, infrared observations
  55. GRB 050525: observatons of the optical afterglow
  56. GRB050525: ROTSE-III Refined Analysis
  57. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  58. XRF050522: Radio Observations
  59. Swift/UVOT observation of XRF 050522
  60. GRB 050509A: Further I-band imaging
  61. GRB050522,optical observation
  62. GRB050520,optical observation
  63. XRF 050522: Continued NIR P200 Monitoring
  64. RBO Observations of GRB050522
  65. Recent GRB BVRcIc field photometry
  66. GRB050520: Radio Observations
  67. XRF 050522: Swift XRT observation
  68. XRF050522, BVRcIc field photometry
  69. XRF050522: Optical Observations
  70. XRF050522: Near-infrared Observations
  71. GRB 050520: VLT/ULTRACAM observations
  72. GRB 050520: Swift XRT refined analysis
  73. XRF050509C: Chandra Afterglow Detection
  74. XRF050509c: Radio Observations
  75. GRB 050520: P200 Observations
  76. GRB 050520: TAROT optical limit
  77. GRB 050520: VLT/ULTRACAM observations
  78. XRF 050509c optical afterglow
  79. GRB 050509B and short GRB-SN association? (corrected)
  80. GRB 050509B and short GRB-SN association?
  81. GRB050502b: Early Observation
  82. GRB050509b, Bok telescope B-band imaging
  83. Refined Chandra analysis of GRB 050509b
  84. GRB050509b, SDSS pre-burst observations
  85. GRB 050509b: Keck/Chandra Cross-Correlation
  86. GRB 050509b: Keck/Chandra Cross-Correlation
  87. Chandra observation of GRB 050509b
  88. GRB 050509b: RAPTOR deep, early limits.
  89. GRB050509B: Optical observations at the Very Large Telescope
  90. GRB 050509b: No Optical Variability in XRT Error Circle
  91. GRB 050509a: Swift-BAT refined analysis
  92. GRB 050509c: ROTSE-III Optical Limits
  93. GRB 050505, early TAROT observation
  94. GRB050509c: REM NIR and Optical observations
  95. GRB 050509b: Physical Properties of the Candidate Host galaxy
  96. GRB 050505: SARA Observations
  97. GRB 050509B, Optical Observations
  98. GRB 050509B: Swift/XRT refined analysis
  99. GRB 050509b: Optical observations
  100. GRB 050509A: Optical observations

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