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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"

45643 results found.

  1. GRB050525a: HST Observations
  2. CORRECTION: GRB050603 Swift UVOT Afterglow Observations
  3. H3804: A Possible New XRB Detected by HETE
  4. H3800 and H3801 on 2005 June 11: two bursts from SGR1806-20 localized by HETE
  5. XRF 050509c: Optical monitoring
  6. Konus-Wind observation of an intermediate burst from SGR 1806-20
  7. IBAS Alert #2512 is NOT a GRB
  8. XRF050509c: Radio Detection
  9. GRB 050416(a): Host Galaxy Redshift Determination
  10. GRB 050607: MDM Observation
  11. GRB 050607 optical decay
  12. GRB 050607: RTT150 optical observations
  13. GRB050607: refined analysis of prompt REM observations
  14. Swift/UVOT observations of GRB050607
  15. GRB 050607 : Lulin R-band observation
  16. GRB 050607: PROMPT VRcIc Observations
  17. GRB 050607: RAPTOR-S Early Optical Limits
  18. GRB050607: KAIT optical limits
  19. GRB 050525a, Mid-Infrared Observations
  20. GRB 050607: Optical decay and spectral slope
  21. GRB 050607: MDM Observations
  22. GRB050607,optical observation
  23. GRB 050607 - XRT refined data analysis
  24. Optical Afterglow of GRB 050607
  25. GRB050607 optical limit by "Pi of the Sky"
  26. GRB050607: Swift Detection of a long GRB
  27. GRB050607: P60 Observations
  28. GRB050607: prompt REM observations
  29. GRB 050603: prediction of t_break
  30. Limits on a SN in the field of GRB 050509b
  31. GRB 050603: Redshift
  32. GRB 050603 - XRT data analysis of the first day
  33. Konus-Wind observation of GRB 050603
  34. GRB 050603: Analysis of UVOT data
  35. GRB050603: Fading Afterglow observed by Swift UVOT
  36. GRB050603, submillimetre observations
  37. GRB 050603: Swift XRT Position
  38. GRB050603: Radio Detection
  39. GRB 050603: Swift-BAT refined analysis of a long three-spiked burst
  40. GRB 050603: Afterglow Identification from LCO
  41. GRB 050603: INTEGRAL shows it is not a short GRB
  42. Swift/BAT Detection of GRB050603
  43. GRB 050408: jet break in the XRT light curve
  44. GRB 050525a, infrared observations
  45. GRB 050525a, SMARTS optical/IR afterglow observations
  46. GRB050528, XRT observations
  47. Correction to GCN Circ 3502 on GRB 050528
  48. GRB050528: updated Liverpool Telescope limits
  49. Swift-BAT GRB 050528: a soft burst
  50. Update on Swift-BAT GRB 050528 (Trigger 130679)
  51. GRB050528: BOOTES optical candidate (retraction)
  52. GRB050504: Ashra-P2/3 monitor and Ashra-AFT response
  53. GRB050528: BOOTES optical candidate
  54. Possible GRB050528: no candidate from Liverpool Telescope
  55. Swift-BAT detection of possible GRB 050528
  56. GRB050525a: Radio Observations
  57. GRB 050509b: refined XRT/Chandra afterglow position analysis
  58. GRB 050525: RTT150, Optical observations
  59. GRB050525a: optical upper limits
  60. GRB 050525a: SARA Observations
  61. GRB 050525B: Swift-BAT observations
  62. GRB 050525: MITSuME Optical Observation in VRI
  63. GRB 050525a: MDM Observations
  64. GRB050525A,optical observation
  65. GRB 050525 : Lulin optical afterglow observations
  66. GRB050525: Super-LOTIS observations
  67. GRB 050525, spectral lag pseudo-redshift
  68. GRB 050525a: Gemini/GMOS Spectra
  69. GRB050306: optical afterglow not confirmed
  70. GRB 050525: BART optical observation
  71. GRB 050525A: BOOTES simultaneous optical observations
  72. GRB 050525A: Swift-BAT refined analysis
  73. GRB050525: Optical observations
  74. GRB 050525B: INTEGRAL shows it is unrelated to GRB050525A
  75. GRB 050525: pseudo-redshift
  76. Swift/UVOT UV and optical detections of GRB 050525
  77. Konus-Wind observation of GRB 050525
  78. GRB 050525: TAROT observations of the early afterglow
  79. INTEGRAL detection of GRB 050525
  80. GRB 050525, infrared observations
  81. GRB 050525: Optical observation
  82. GRB 050525: observatons of the optical afterglow
  83. GRB050525: ROTSE-III Refined Analysis
  84. GRB 050525 - Very Bright, Not Short
  85. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  86. GRB 050525A: ROTSE-III Detection of Possible Counterpart
  87. XRF050522: NIR observations of XRT candidate
  88. XRF 050522: Swift XRT refined analysis
  89. XRF050522: Radio Observations
  90. Swift/UVOT observation of XRF 050522
  91. GRB 050509A: Further I-band imaging
  92. GRB050522,optical observation
  93. GRB050520,optical observation
  94. XRF 050522: Continued NIR P200 Monitoring
  95. RBO Observations of GRB050522
  96. GRB050509b: optical observations
  97. Recent GRB BVRcIc field photometry
  98. GRB050520: Radio Observations
  99. XRF 050522: Swift XRT observation
  100. XRF050522, BVRcIc field photometry

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