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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"

32489 results found.

  1. X-ray Afterglow of GRB 000529
  2. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  3. IPN localization and time history of GRB000528
  4. New IPN localization of GRB000529
  5. GRB000519: Optical observations
  6. IPN localization of GRB000529
  7. GRB 000528 - WFC measurements
  8. IPN triangulation of GRB000519
  9. Re: GRB000508B : Optical observations
  10. GRB 000418, Optical observation
  11. GRB000508B, optical photometry
  12. Possible GRB-related phenomenon
  13. GRB 000424 Optical Observations
  14. The redshift of GRB 000418
  15. GRB000424, optical observations
  16. GRB 000429, optical observation
  17. GRB000418, Radio detection
  18. GRB000418, K'-band photometry
  19. GRB 000418, Optical Observation
  20. GRB 000418, optical observation
  21. GRB000424 Optical Observations
  22. GRB 000418, Optical Observation
  23. GRB000424, optical observations
  24. GRB000424, optical observations
  25. GRB 000424, Optical Observations
  26. GRB 000418, Optical Observation
  27. GRB000418, near-infrared observations
  28. BeppoSAX GRB000424
  29. Correction to IPN error box for GRB000419
  30. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  31. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  32. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  33. GRB 000408, optical observations
  34. Refined IPN error box for GRB000408
  35. GRB000301c results
  36. GRB000408: Optical CCD Observations from MIRO
  37. GRB000408, lotis optical observations
  38. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  39. GRB000326 Optical Observations
  40. GRB000301C - Addendum to GCN 623
  41. GRB000326, Further VLA observations
  42. GRB 000323, optical observations
  43. GRB 000326: Optical Observations
  44. GRB000326, Radio observations
  45. GRB 000307 optical observations
  46. Single error box for GRB000315
  47. GRB000313, Radio observations
  48. GRB000301C - B and R photometry
  49. GRB 000307, Optical Observations
  50. GRB 000301C: Optical Spectrum and Redshift
  51. GRB 000301C: Optical Spectrum and Redshift
  52. GRB 000301C: A Precise Redshift Determination
  53. GRB 000301C, Optical Observation
  54. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  55. GRB 000301C: HST/STIS CCD Imaging of the field
  56. GRB000301C, optical R-band observations
  57. GRB000301c - R photometry and nearby faint source confirmation
  58. GRB 000301C, Optical Observation
  59. GRB 000301C Optical Observations
  60. GRB 000301C: K' Observations
  61. GRB000301C OT candidate optical observations
  62. Optical observations of GRB000301c
  63. GRB000301C, Radio observations
  64. GRB000301C, Radio observations
  65. GRB000301C, near-infrared observations (JHK' imaging)
  66. GRB 000301C, Optical Color
  67. GRB 000301C, UBVRI field photometry
  68. GRB 000301C, Optical Observation
  69. GRB000301C, optical observations
  70. GRB000301C 250 GHz detection
  71. GRB 000301C R-band observation
  72. GRB 000301C, Optical Observation
  73. GRB000301C, near-infrared observations (JHK' photometry)
  74. GRB 000301C: OT confirmed
  75. GRB000301c optical observations
  76. GRB 000301A, Radio Observations
  77. GRB000301C, optical observations
  78. GRB000301c, near-infrared observations
  79. GRB000301C
  80. GRB 000301C : Optical Candidate
  81. Radio observations of the error box of GRB000301A
  82. HST Observations of GRB 990712
  83. GRB 000115 Optical observations
  84. GRB 000214, Radio Observations
  85. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  86. GRB000210, Radio Observations
  87. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  88. IPN annulus for GRB000214
  89. Optical observations of GRB000210
  90. GRB000210 X-ray afterglow
  91. GRB 000210: BATSE Observations
  92. Correction to Chandra Position of GRB000210 afterglow
  93. Optical observations of the Chandra X-ray source for GRB000210
  94. GRB000210, Radio Observations
  95. Optical candidate for GRB000210
  96. Chandra Observations of GRB000210 X-ray Afterglow
  97. IPN triangulation of GRB000210
  98. GRB000201, Radio Observations
  99. Optical observations of GRB000131
  100. GRB000201 Optical Observations

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Download all Circulars as a .tar.gz archive (updated once a day):
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