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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"

45655 results found.

  1. GRB 000418, optical observation
  2. GRB000424 Optical Observations
  3. GRB 000418, Optical Observation
  4. GRB000424, optical observations
  5. GRB000424, optical observations
  6. GRB 000424, Optical Observations
  7. GRB 000418, Optical Observation
  8. GRB000418, near-infrared observations
  9. BeppoSAX GRB000424
  10. Correction to IPN error box for GRB000419
  11. IPN error box for GRB000418
  12. GRB000419 [IPN Position]
  13. GRB000416 Optical Observations
  14. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  15. GRB000416 BRJK observations
  16. 1SAXJ1715.0-7134 refined position
  17. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  18. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  19. Budget cuts in BeppoSAX operations: impact on GRB observations
  20. GRB 000408, optical observations
  21. Refined IPN error box for GRB000408
  22. GRB 991208, UBVRI field photometry
  23. GRB000301c results
  24. GRB000408: Optical CCD Observations from MIRO
  25. GRB000408, lotis optical observations
  26. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  27. GRB000408 [IPN Position]
  28. GRB000326 Optical Observations
  29. GRB000301C - Addendum to GCN 623
  30. GRB000301C - R magnitude lower limit
  31. GRB000326, Further VLA observations
  32. GRB 000323, optical observations
  33. GRB 000326: Optical Observations
  34. GRB000326, Radio observations
  35. GRB000326 [IPN Position]
  36. GRB 000307 optical observations
  37. GRB000323 [IPN Position]
  38. Single error box for GRB000315
  39. GRB000315 [IPN Positions]
  40. GRB000313, Radio observations
  41. GRB 000313 - optical transient in the BATSE error box
  42. GRB000301C - B and R photometry
  43. GRB000301C - R photometry
  44. GRB 000307, Optical Observations
  45. GRB 000307, BVRI Field Photometry
  46. GRB 000301C: Optical Spectrum and Redshift
  47. GRB 000301C: Optical Spectrum and Redshift
  48. GRB 000301C: A Precise Redshift Determination
  49. GRB 000301C, Optical Observation
  50. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  51. GRB 000301C: HST/STIS CCD Imaging of the field
  52. IPN error box for GRB000307
  53. GRB 000301c: K' observations
  54. GRB000301C, optical R-band observations
  55. GRB000301c - R photometry and nearby faint source confirmation
  56. GRB 000301C, Optical Observation
  57. GRB 000301c: K' observations
  58. GRB 000301C Optical Observations
  59. GRB 000301C: K' Observations
  60. GRB000301C OT candidate optical observations
  61. GRB000301C - Host galaxy not detected in R (?)
  62. Optical observations of GRB000301c
  63. GRB000301C, Radio observations
  64. GRB000301C, Radio observations
  65. GRB000301C optical observations
  66. GRB000301C, near-infrared observations (JHK' imaging)
  67. GRB 000301c near-IR observations
  68. GRB 000301C, Optical Color
  69. GRB000301C, Optical Spectroscopy
  70. GRB 000301C, UBVRI field photometry
  71. GRB 000301C, Optical Observation
  72. GRB000301C, optical observations
  73. GRB000301C 250 GHz detection
  74. GRB 000301C R-band observation
  75. GRB 000301C, Optical Observation
  76. GRB000301C, near-infrared observations (JHK' photometry)
  77. GRB 000301C: OT confirmed
  78. GRB000301c optical observations
  79. GRB 000301A, Radio Observations
  80. GRB000301C, optical observations
  81. GRB000301c, near-infrared observations
  82. GRB000301C
  83. GRB 000301C : Optical Candidate
  84. Radio observations of the error box of GRB000301A
  85. GRB000301C: RXTE/ASM and IPN localizations
  86. GRB000301A [IPN Position]
  87. GRB000226 [IPN Position]
  88. HST Observations of GRB 990712
  89. GRB 000214 near-IR observations
  90. GRB 000115 Optical observations
  91. GRB 000214, Radio Observations
  92. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  93. GRB000210, Radio Observations
  94. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  95. GRB 000115, BVRI field photometry
  96. GRB000214: BeppoSAX GRBM and WFC Detection
  97. IPN annulus for GRB000214
  98. BATSE GRB trigger criterion changed
  99. Optical observations of GRB000210
  100. GRB000210 X-ray afterglow

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