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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"

28084 results found.

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

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