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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"

18353 results found.

  1. Possible GRB050528: no candidate from Liverpool Telescope
  2. GRB050525a: Radio Observations
  3. GRB 050509b: refined XRT/Chandra afterglow position analysis
  4. GRB 050525: RTT150, Optical observations
  5. GRB 050525a: SARA Observations
  6. GRB 050525B: Swift-BAT observations
  7. GRB 050525: MITSuME Optical Observation in VRI
  8. GRB050525A,optical observation
  9. GRB050525: Super-LOTIS observations
  10. GRB050306: optical afterglow not confirmed
  11. GRB 050525: BART optical observation
  12. GRB 050525A: BOOTES simultaneous optical observations
  13. GRB050525: Optical observations
  14. GRB 050525B: INTEGRAL shows it is unrelated to GRB050525A
  15. GRB 050525: TAROT observations of the early afterglow
  16. INTEGRAL detection of GRB 050525
  17. GRB 050525, infrared observations
  18. GRB 050525: observatons of the optical afterglow
  19. GRB050525: ROTSE-III Refined Analysis
  20. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  21. XRF050522: Radio Observations
  22. Swift/UVOT observation of XRF 050522
  23. GRB 050509A: Further I-band imaging
  24. GRB050522,optical observation
  25. GRB050520,optical observation
  26. XRF 050522: Continued NIR P200 Monitoring
  27. GRB050509b: optical observations
  28. Recent GRB BVRcIc field photometry
  29. GRB050520: Radio Observations
  30. XRF 050522: Swift XRT observation
  31. XRF050522, BVRcIc field photometry
  32. XRF050522: Optical Observations
  33. XRF050522: Near-infrared Observations
  34. GRB 050520: VLT/ULTRACAM observations
  35. XRF050509c: Radio Observations
  36. GRB 050520: P200 Observations
  37. GRB 050520: TAROT optical limit
  38. GRB 050520: VLT/ULTRACAM observations
  39. GRB 050509B: Subaru Optical Observations
  40. GRB050502b: Early Observation
  41. GRB050509b, Bok telescope B-band imaging
  42. GRB050509b, SDSS pre-burst observations
  43. GRB 050509b: Keck/Chandra Cross-Correlation
  44. GRB 050509b: Keck/Chandra Cross-Correlation
  45. Chandra observation of GRB 050509b
  46. GRB050509B: Optical observations at the Very Large Telescope
  47. GRB 050509b: No Optical Variability in XRT Error Circle
  48. GRB 050509c: ROTSE-III Optical Limits
  49. GRB 050509B: WSRT Radio Observations
  50. GRB 050505, early TAROT observation
  51. GRB050509c (=H3751): An X-Ray Flash Localized By HETE
  52. GRB050509c: REM NIR and Optical observations
  53. GRB 050505: SARA Observations
  54. GRB 050509b: Optical observations
  55. GRB 050509b: Possible Optical Counterpart
  56. GRB 050509A: Optical observations
  57. GRB050509b: Radio Observations
  58. Swift Detection of GRB050509b: A short duration burst
  59. Swift Detection of the Burst GRB050509
  60. GRB 050505, simultaneous optical observation
  61. GRB050505: AAVSO observations
  62. GRB050416A : 1 GHz limit from GMRT
  63. GRB050505: Optical Afterglow Candidate
  64. GRB 050505: Swift XRT Position
  65. GRB 050416b:Swift XRT afterglow upper limits
  66. GRB 050416b:Swift XRT afterglow upper limits
  67. GRB050502b: Afterglow Confirmation: Correction to OT Coordinates
  68. GRB050502b: Afterglow Confirmation
  69. GRB050502: P200 Observations (Correction)
  70. GRB050502: P200 Observations
  71. Swift UVOT observation of GRB 050504
  72. GRB050504: P60 Observations
  73. GRB (?) 050504: IR Observations, Intriguing Source
  74. GRB 050502b, Optical observations
  75. GRB050502a: P60 Observations (Correction)
  76. GRB050502a: P60 Observations
  77. GRB050502B Swift-BAT refined analysis
  78. GRB050502B: I band source in XRT error circle
  79. Swift UVOT refined analysis
  80. GRB050502B: Optical Limits from ANU 1m
  81. GRB 050502: ROTSE-III Detection of Possible Counterpart
  82. Swift/BAT possible detection of a weak burst GRB050430
  83. GRB050416a: Radio Detection
  84. Swift Detection of GRB 050422
  85. GRB 050421: SLOTIS observations
  86. GRB 050421: Further Analysis of IR imaging
  87. GRB050421: Radio Observations
  88. GRB050421: Radio Observations
  89. GRB 050421: Swift-UVOT observation
  90. GRB 050421: IR Observations
  91. GRB050421
  92. GRB 050421: NIR observations
  93. GRB050421: P60 Observations
  94. GRB 050421: BOOTES-2 simultaneous optical observations
  95. GRB 050416b: Tentative Swift XRT Position
  96. GRB 050315: potential host galaxy
  97. GRB050326: analysis of the XMM-Newton observation
  98. GRB050418: Null Optical Observations
  99. GRB050416A, optical observations
  100. GRB 050416: Mitsume optical observation

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