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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').
  1. GRB000519, BVRI field photometry
  2. IPN triangulation of GRB000519
  3. IPN triangulation of GRB000516
  4. Re: GRB000508B : Optical observations
  5. GRB 000418, Optical observation
  6. GRB000508B, optical photometry
  7. GRB000508B, BVR field photometry
  8. Possible GRB-related phenomenon
  9. RXTE/ASM and IPN localization of GRB 000508B
  10. GRB000424, UBVRI field photometry
  11. GRB 000424 Optical Observations
  12. GRB000418, UBVRI field photometry update
  13. The redshift of GRB 000418
  14. GRB000424, optical observations
  15. GRB 000429, optical observation
  16. GRB 000429, UBVRI field photometry
  17. IPN localization of GRB000429
  18. GRB 000418, UBVRI field photometry
  19. GRB000418, Radio detection
  20. GRB000418, K'-band photometry
  21. GRB 000418, Optical Observation
  22. GRB 000418, optical observation
  23. GRB000424 Optical Observations
  24. GRB 000418, Optical Observation
  25. GRB000424, optical observations
  26. GRB000424, optical observations
  27. GRB 000424, Optical Observations
  28. GRB 000418, Optical Observation
  29. GRB000418, near-infrared observations
  30. BeppoSAX GRB000424
  31. Correction to IPN error box for GRB000419
  32. IPN error box for GRB000418
  33. GRB000419 [IPN Position]
  34. GRB000416 Optical Observations
  35. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  36. GRB000416 BRJK observations
  37. 1SAXJ1715.0-7134 refined position
  38. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  39. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  40. Budget cuts in BeppoSAX operations: impact on GRB observations
  41. GRB 000408, optical observations
  42. Refined IPN error box for GRB000408
  43. GRB 991208, UBVRI field photometry
  44. GRB000301c results
  45. GRB000408: Optical CCD Observations from MIRO
  46. GRB000408, lotis optical observations
  47. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  48. GRB000408 [IPN Position]
  49. GRB000326 Optical Observations
  50. GRB000301C - Addendum to GCN 623
  51. GRB000301C - R magnitude lower limit
  52. GRB000326, Further VLA observations
  53. GRB 000323, optical observations
  54. GRB 000326: Optical Observations
  55. GRB000326, Radio observations
  56. GRB000326 [IPN Position]
  57. GRB 000307 optical observations
  58. GRB000323 [IPN Position]
  59. Single error box for GRB000315
  60. GRB000315 [IPN Positions]
  61. GRB000313, Radio observations
  62. GRB 000313 - optical transient in the BATSE error box
  63. GRB000301C - B and R photometry
  64. GRB000301C - R photometry
  65. GRB 000307, Optical Observations
  66. GRB 000307, BVRI Field Photometry
  67. GRB 000301C: Optical Spectrum and Redshift
  68. GRB 000301C: Optical Spectrum and Redshift
  69. GRB 000301C: A Precise Redshift Determination
  70. GRB 000301C, Optical Observation
  71. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  72. GRB 000301C: HST/STIS CCD Imaging of the field
  73. IPN error box for GRB000307
  74. GRB 000301c: K' observations
  75. GRB000301C, optical R-band observations
  76. GRB000301c - R photometry and nearby faint source confirmation
  77. GRB 000301C, Optical Observation
  78. GRB 000301c: K' observations
  79. GRB 000301C Optical Observations
  80. GRB 000301C: K' Observations
  81. GRB000301C OT candidate optical observations
  82. GRB000301C - Host galaxy not detected in R (?)
  83. Optical observations of GRB000301c
  84. GRB000301C, Radio observations
  85. GRB000301C, Radio observations
  86. GRB000301C optical observations
  87. GRB000301C, near-infrared observations (JHK' imaging)
  88. GRB 000301c near-IR observations
  89. GRB 000301C, Optical Color
  90. GRB000301C, Optical Spectroscopy
  91. GRB 000301C, UBVRI field photometry
  92. GRB 000301C, Optical Observation
  93. GRB000301C, optical observations
  94. GRB000301C 250 GHz detection
  95. GRB 000301C R-band observation
  96. GRB 000301C, Optical Observation
  97. GRB000301C, near-infrared observations (JHK' photometry)
  98. GRB 000301C: OT confirmed
  99. GRB000301c optical observations
  100. GRB 000301A, Radio Observations

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