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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"

32500 results found.

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

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