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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"

20258 results found.

  1. GRB050607,optical observation
  2. GRB 050607 - XRT refined data analysis
  3. Optical Afterglow of GRB 050607
  4. GRB050607: Swift Detection of a long GRB
  5. GRB050607: prompt REM observations
  6. Limits on a SN in the field of GRB 050509b
  7. GRB 050603: Redshift
  8. GRB 050603 - XRT data analysis of the first day
  9. Konus-Wind observation of GRB 050603
  10. GRB050603, submillimetre observations
  11. GRB050603: Radio Detection
  12. GRB 050603: Swift-BAT refined analysis of a long three-spiked burst
  13. GRB 050603: INTEGRAL shows it is not a short GRB
  14. GRB 050525a, infrared observations
  15. GRB050528: updated Liverpool Telescope limits
  16. GRB050504: Ashra-P2/3 monitor and Ashra-AFT response
  17. Possible GRB050528: no candidate from Liverpool Telescope
  18. GRB050525a: Radio Observations
  19. GRB 050509b: refined XRT/Chandra afterglow position analysis
  20. GRB 050525: RTT150, Optical observations
  21. GRB 050525a: SARA Observations
  22. GRB 050525B: Swift-BAT observations
  23. GRB 050525: MITSuME Optical Observation in VRI
  24. GRB050525A,optical observation
  25. GRB050525: Super-LOTIS observations
  26. GRB050306: optical afterglow not confirmed
  27. GRB 050525: BART optical observation
  28. GRB 050525A: BOOTES simultaneous optical observations
  29. GRB 050525A: Swift-BAT refined analysis
  30. GRB050525: Optical observations
  31. GRB 050525B: INTEGRAL shows it is unrelated to GRB050525A
  32. Konus-Wind observation of GRB 050525
  33. GRB 050525: TAROT observations of the early afterglow
  34. INTEGRAL detection of GRB 050525
  35. GRB 050525, infrared observations
  36. GRB 050525: observatons of the optical afterglow
  37. GRB050525: ROTSE-III Refined Analysis
  38. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  39. XRF 050522: Swift XRT refined analysis
  40. XRF050522: Radio Observations
  41. Swift/UVOT observation of XRF 050522
  42. GRB 050509A: Further I-band imaging
  43. GRB050522,optical observation
  44. GRB050520,optical observation
  45. XRF 050522: Continued NIR P200 Monitoring
  46. Recent GRB BVRcIc field photometry
  47. GRB050520: Radio Observations
  48. XRF 050522: Swift XRT observation
  49. XRF050522, BVRcIc field photometry
  50. XRF050522: Optical Observations
  51. XRF050522: Near-infrared Observations
  52. GRB 050520: VLT/ULTRACAM observations
  53. Swift UVOT Observations of GRB 050520
  54. GRB 050520: Swift XRT refined analysis
  55. XRF050509c: Radio Observations
  56. RBO Observations of GRB050520
  57. GRB 050520: P200 Observations
  58. GRB 050520: TAROT optical limit
  59. GRB 050520: Swift XRT position
  60. GRB 050520: VLT/ULTRACAM observations
  61. GRB 050509B and short GRB-SN association? (corrected)
  62. GRB 050509B and short GRB-SN association?
  63. GRB050502b: Early Observation
  64. GRB050509b, Bok telescope B-band imaging
  65. GRB050509b, SDSS pre-burst observations
  66. GRB 050509b: Keck/Chandra Cross-Correlation
  67. GRB 050509b: Keck/Chandra Cross-Correlation
  68. Chandra observation of GRB 050509b
  69. GRB 050509b: RAPTOR deep, early limits.
  70. GRB050509B: Optical observations at the Very Large Telescope
  71. GRB 050509b: No Optical Variability in XRT Error Circle
  72. GRB 050509c: ROTSE-III Optical Limits
  73. GRB 050505, early TAROT observation
  74. GRB050509c: REM NIR and Optical observations
  75. GRB 050505: SARA Observations
  76. Swift UVOT Follow-up Observations of GRB 050509B
  77. GRB 050509A: Optical observations
  78. GRB050509b: Radio Observations
  79. GRB 050509B: ROTSE-III Optical Limits
  80. Swift Detection of GRB050509b: A short duration burst
  81. Swift Detection of the Burst GRB050509
  82. GRB 050505: Keck I-band Magnitude
  83. GRB 050505, simultaneous optical observation
  84. GRB 050505: Further Swift UVOT observations.
  85. GRB050505: AAVSO observations
  86. GRB050416A : 1 GHz limit from GMRT
  87. GRB 050505 UVOT
  88. GRB050505: Optical Afterglow Candidate
  89. GRB 050416b:Swift XRT afterglow upper limits
  90. GRB 050416b:Swift XRT afterglow upper limits
  91. GRB050502b: Afterglow Confirmation: Correction to OT Coordinates
  92. GRB050502b: Afterglow Confirmation
  93. GRB050502: P200 Observations (Correction)
  94. GRB050502: P200 Observations
  95. Swift UVOT observation of GRB 050504
  96. GRB050504: P60 Observations
  97. GRB (?) 050504: IR Observations, Intriguing Source
  98. GRB 050502b, Optical observations
  99. GRB050502a: P60 Observations (Correction)
  100. GRB050502a: P60 Observations

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