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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"

44754 results found.

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

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