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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"

32501 results found.

  1. GRB 000301C: Further Late-Time HST/STIS observations
  2. GRB000528: follow-up X-ray measurements and update of IPN annulus
  3. Optical Follow-up of GRB000529 Error Box
  4. GRB000607, Radio Observations
  5. GRB000604 optical non-detection
  6. GRB000604 - Optical observations
  7. GRB000604, optical observations
  8. GRB000528, optical observations at ESO
  9. GRB 000604 optical observations
  10. GRB 000418: Detection of the Host Galaxy
  11. GRB000604, optical observations, comparison with DPOSS
  12. GRB000528, Radio Observations
  13. X-ray Afterglow of GRB 000529
  14. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  15. IPN localization and time history of GRB000528
  16. New IPN localization of GRB000529
  17. GRB000519: Optical observations
  18. IPN localization of GRB000529
  19. GRB 000528 - WFC measurements
  20. IPN triangulation of GRB000519
  21. Re: GRB000508B : Optical observations
  22. GRB 000418, Optical observation
  23. GRB000508B, optical photometry
  24. Possible GRB-related phenomenon
  25. GRB 000424 Optical Observations
  26. The redshift of GRB 000418
  27. GRB000424, optical observations
  28. GRB 000429, optical observation
  29. GRB000418, Radio detection
  30. GRB000418, K'-band photometry
  31. GRB 000418, Optical Observation
  32. GRB 000418, optical observation
  33. GRB000424 Optical Observations
  34. GRB 000418, Optical Observation
  35. GRB000424, optical observations
  36. GRB000424, optical observations
  37. GRB 000424, Optical Observations
  38. GRB 000418, Optical Observation
  39. GRB000418, near-infrared observations
  40. BeppoSAX GRB000424
  41. Correction to IPN error box for GRB000419
  42. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  43. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  44. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  45. GRB 000408, optical observations
  46. Refined IPN error box for GRB000408
  47. GRB000301c results
  48. GRB000408: Optical CCD Observations from MIRO
  49. GRB000408, lotis optical observations
  50. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  51. GRB000326 Optical Observations
  52. GRB000301C - Addendum to GCN 623
  53. GRB000326, Further VLA observations
  54. GRB 000323, optical observations
  55. GRB 000326: Optical Observations
  56. GRB000326, Radio observations
  57. GRB 000307 optical observations
  58. Single error box for GRB000315
  59. GRB000313, Radio observations
  60. GRB000301C - B and R photometry
  61. GRB 000307, Optical Observations
  62. GRB 000301C: Optical Spectrum and Redshift
  63. GRB 000301C: Optical Spectrum and Redshift
  64. GRB 000301C: A Precise Redshift Determination
  65. GRB 000301C, Optical Observation
  66. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  67. GRB 000301C: HST/STIS CCD Imaging of the field
  68. GRB000301C, optical R-band observations
  69. GRB000301c - R photometry and nearby faint source confirmation
  70. GRB 000301C, Optical Observation
  71. GRB 000301C Optical Observations
  72. GRB 000301C: K' Observations
  73. GRB000301C OT candidate optical observations
  74. Optical observations of GRB000301c
  75. GRB000301C, Radio observations
  76. GRB000301C, Radio observations
  77. GRB000301C, near-infrared observations (JHK' imaging)
  78. GRB 000301C, Optical Color
  79. GRB 000301C, UBVRI field photometry
  80. GRB 000301C, Optical Observation
  81. GRB000301C, optical observations
  82. GRB000301C 250 GHz detection
  83. GRB 000301C R-band observation
  84. GRB 000301C, Optical Observation
  85. GRB000301C, near-infrared observations (JHK' photometry)
  86. GRB 000301C: OT confirmed
  87. GRB000301c optical observations
  88. GRB 000301A, Radio Observations
  89. GRB000301C, optical observations
  90. GRB000301c, near-infrared observations
  91. GRB000301C
  92. GRB 000301C : Optical Candidate
  93. Radio observations of the error box of GRB000301A
  94. HST Observations of GRB 990712
  95. GRB 000115 Optical observations
  96. GRB 000214, Radio Observations
  97. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  98. GRB000210, Radio Observations
  99. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  100. IPN annulus for GRB000214

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