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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"

32490 results found.

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

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