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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"

36155 results found.

  1. GRB 050504: Swift XRT afterglow candidate has faded
  2. XRF 050509c optical afterglow
  3. GRB 050509B and short GRB-SN association? (corrected)
  4. GRB 050509B and short GRB-SN association?
  5. GRB 050509B: Subaru Optical Observations
  6. GRB050502b: Early Observation
  7. GRB050509b, Bok telescope B-band imaging
  8. Refined Chandra analysis of GRB 050509b
  9. GRB050509b, SDSS pre-burst observations
  10. GRB 050509b: Keck/Chandra Cross-Correlation
  11. GRB 050509b: Keck/Chandra Cross-Correlation
  12. Chandra observation of GRB 050509b
  13. GRB 050509b: RAPTOR deep, early limits.
  14. GRB050509B: Optical/Infared observations
  15. GRB 050509b: Swift/UVOT follow-up measurements
  16. GRB 050509b Milagro GeV/TeV Observations
  17. GRB050509B: Optical observations at the Very Large Telescope
  18. GRB 050509b: No Optical Variability in XRT Error Circle
  19. GRB 050509a: Swift-BAT refined analysis
  20. GRB 050509c: ROTSE-III Optical Limits
  21. GRB 050509B: WSRT Radio Observations
  22. GRB050509c: REM NIR and Optical observations (errata corrige to GCN 3400)
  23. GRB 050505, early TAROT observation
  24. GRB050509c (=H3751): An X-Ray Flash Localized By HETE
  25. GRB 050509b: Further Analysis of Keck LRIS Images
  26. GRB050509c: REM NIR and Optical observations
  27. GRB 050509b: Physical Properties of the Candidate Host galaxy
  28. GRB 050505: SARA Observations
  29. Swift UVOT Follow-up Observations of GRB 050509B
  30. GRB 050509B, Optical Observations
  31. GRB 050509B: Swift/XRT refined analysis
  32. GRB 050509b: Optical observations
  33. GRB 050509b: Precision Astrometry
  34. GRB 050509b: Possible Optical Counterpart
  35. Keck/DEIMOS Spectrum of Possible Host Galaxy for GRB050509b
  36. GRB 050509A: Optical observations
  37. GRB 050509b: Optical Counterpart Candidate
  38. GRB 050509b: PAIRITEL and WIYN Observations
  39. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  40. GRB 050509b: optical observations
  41. GRB 050509b: Swift XRT Position
  42. GRB 050509B: ROTSE-III Optical Limits
  43. GRB 050509a: Swift XRT Position
  44. Swift-BAT detection of GRB 050507
  45. GRB 050505: Keck I-band Magnitude
  46. GRB 050505: early time observations
  47. GRB 050505 - Faulkes Telescope North observations
  48. GRB 050502a: Swift XRT Upper Limit
  49. GRB 050505, simultaneous optical observation
  50. GRB 050505: Further Swift UVOT observations.
  51. GRB050505: AAVSO observations
  52. GRB050416A : 1 GHz limit from GMRT
  53. GRB 050505: Keck absorption spectrum and redshift (z=4.27)
  54. GRB 050505 UVOT
  55. GRB050505: Optical Afterglow Candidate
  56. GRB 050505: Swift XRT Position
  57. GRB 050502a: Optical Observations
  58. GRB 050416b:Swift XRT afterglow upper limits
  59. GRB 050416b:Swift XRT afterglow upper limits
  60. GRB 050504: Swift XRT position
  61. GRB050502: P200 Observations (Correction)
  62. GRB050502: P200 Observations
  63. GRB 050504 : R band observation at Lulin observatory
  64. Swift UVOT observation of GRB 050504
  65. GRB 050504, R band Observations
  66. GRB 050502b, V band Observations
  67. GRB050504: P60 Observations
  68. GRB 050504: A long GRB detected with INTEGRAL
  69. GRB (?) 050504: IR Observations, Intriguing Source
  70. GRB 050502b, Optical observations
  71. GRB050502a: P60 Observations (Correction)
  72. GRB050502a: P60 Observations
  73. Renewal of SGR 1806-20 activity
  74. GRB 050502a: RBO Observations
  75. GRB 050502A: WSRT Radio Observations
  76. GRB050502A: Optical Observations
  77. Swift UVOT refined analysis
  78. Retraction of Swift-BAT trigger 116145
  79. GRB 050502a : R band observation at Lulin observatory
  80. GRB 050502b : optical observation at Lulin observatory
  81. GRB 050502b: Swift XRT Position
  82. GRB 050502A: Redshift measurement based on Keck HIRES Observations
  83. GRB 050502: INTEGRAL results
  84. GRB050502: ANU 1m optical Observations
  85. GRB 050502: Confirmed variability of the afterglow candidate +
  86. GRB 050502: PAIRITEL IR Observations
  87. GRB050502 - Correction on the Optical Candidate from the Liverpool
  88. GRB 050502 - A long GRB detected with INTEGRAL
  89. GRB 050502: ROTSE-III Detection of Possible Counterpart
  90. Swift-BAT Trigger 115881 is not a real GRB
  91. Swift/BAT possible detection of a weak burst GRB050430
  92. GRB 050401: Rc observation
  93. GRB050416a: Radio Detection
  94. GRB 050422: Swift-UVOT observation
  95. GRB 050422: Swift-BAT refined analysis
  96. GRB 050422: Swift XRT Position
  97. Swift Detection of GRB 050422
  98. GRB 050421: NIR observations
  99. GRB 050416: Optical/NIR observations
  100. GRB 050421: SLOTIS observations

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