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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"

24885 results found.

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

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