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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"

28051 results found.

  1. GRB 050509b: refined XRT/Chandra afterglow position analysis
  2. GRB 050525: RTT150, Optical observations
  3. GRB 050525a: SARA Observations
  4. GRB 050525B: Swift-BAT observations
  5. GRB 050525: MITSuME Optical Observation in VRI
  6. GRB050525A,optical observation
  7. GRB050525: Super-LOTIS observations
  8. GRB 050525, spectral lag pseudo-redshift
  9. GRB050306: optical afterglow not confirmed
  10. GRB 050525: BART optical observation
  11. GRB 050525A: BOOTES simultaneous optical observations
  12. GRB 050525A: Swift-BAT refined analysis
  13. GRB050525: Optical observations
  14. GRB 050525B: INTEGRAL shows it is unrelated to GRB050525A
  15. Konus-Wind observation of GRB 050525
  16. GRB 050525: TAROT observations of the early afterglow
  17. INTEGRAL detection of GRB 050525
  18. GRB 050525, infrared observations
  19. GRB 050525: observatons of the optical afterglow
  20. GRB050525: ROTSE-III Refined Analysis
  21. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  22. XRF050522: Radio Observations
  23. Swift/UVOT observation of XRF 050522
  24. GRB 050509A: Further I-band imaging
  25. GRB050522,optical observation
  26. GRB050520,optical observation
  27. XRF 050522: Continued NIR P200 Monitoring
  28. RBO Observations of GRB050522
  29. Recent GRB BVRcIc field photometry
  30. GRB050520: Radio Observations
  31. XRF 050522: Swift XRT observation
  32. XRF050522, BVRcIc field photometry
  33. XRF050522: Optical Observations
  34. XRF050522: Near-infrared Observations
  35. GRB 050520: VLT/ULTRACAM observations
  36. GRB 050520: Swift XRT refined analysis
  37. XRF050509C: Chandra Afterglow Detection
  38. XRF050509c: Radio Observations
  39. GRB 050520: P200 Observations
  40. GRB 050520: TAROT optical limit
  41. GRB 050520: VLT/ULTRACAM observations
  42. XRF 050509c optical afterglow
  43. GRB 050509B and short GRB-SN association? (corrected)
  44. GRB 050509B and short GRB-SN association?
  45. GRB050502b: Early Observation
  46. GRB050509b, Bok telescope B-band imaging
  47. Refined Chandra analysis of GRB 050509b
  48. GRB050509b, SDSS pre-burst observations
  49. GRB 050509b: Keck/Chandra Cross-Correlation
  50. GRB 050509b: Keck/Chandra Cross-Correlation
  51. Chandra observation of GRB 050509b
  52. GRB 050509b: RAPTOR deep, early limits.
  53. GRB050509B: Optical observations at the Very Large Telescope
  54. GRB 050509b: No Optical Variability in XRT Error Circle
  55. GRB 050509a: Swift-BAT refined analysis
  56. GRB 050509c: ROTSE-III Optical Limits
  57. GRB 050505, early TAROT observation
  58. GRB050509c: REM NIR and Optical observations
  59. GRB 050509b: Physical Properties of the Candidate Host galaxy
  60. GRB 050505: SARA Observations
  61. GRB 050509B, Optical Observations
  62. GRB 050509B: Swift/XRT refined analysis
  63. GRB 050509b: Optical observations
  64. GRB 050509A: Optical observations
  65. GRB050509b: Radio Observations
  66. GRB 050509b: PAIRITEL and WIYN Observations
  67. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  68. Swift Detection of GRB050509b: A short duration burst
  69. Swift Detection of the Burst GRB050509
  70. GRB 050505: early time observations
  71. GRB 050505, simultaneous optical observation
  72. GRB050505: AAVSO observations
  73. GRB050416A : 1 GHz limit from GMRT
  74. GRB050505: Optical Afterglow Candidate
  75. GRB050505 Swift-BAT refined analysis
  76. GRB 050416b:Swift XRT afterglow upper limits
  77. GRB 050416b:Swift XRT afterglow upper limits
  78. GRB050502b: Afterglow Confirmation: Correction to OT Coordinates
  79. GRB050502b: Afterglow Confirmation
  80. GRB050502: P200 Observations (Correction)
  81. GRB050502: P200 Observations
  82. GRB 050504 : R band observation at Lulin observatory
  83. Swift UVOT observation of GRB 050504
  84. GRB 050504, R band Observations
  85. GRB 050502b, V band Observations
  86. GRB050504: P60 Observations
  87. GRB 050504: A long GRB detected with INTEGRAL
  88. GRB (?) 050504: IR Observations, Intriguing Source
  89. GRB 050502b, Optical observations
  90. GRB050502a: P60 Observations (Correction)
  91. GRB050502a: P60 Observations
  92. Renewal of SGR 1806-20 activity
  93. GRB050502B Swift-BAT refined analysis
  94. Swift UVOT refined analysis
  95. GRB 050502a : R band observation at Lulin observatory
  96. GRB 050502b : optical observation at Lulin observatory
  97. GRB 050502A: Redshift measurement based on Keck HIRES Observations
  98. Swift Detection of the Bright Burst GRB050502b
  99. GRB 050502: INTEGRAL results
  100. GRB 050502: ROTSE-III Detection of Possible Counterpart

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