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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. GRB 000615, near-infrared observations
  2. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  3. GRB000616 [IPN Position]
  4. GRB000615B [IPN Position]
  5. GRB000615, further R-band photometry
  6. GRB 000615: NIR observations
  7. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  8. GRB000615, R-band photometry
  9. GRB000615: BeppoSAX refined coordinates
  10. GRB980425, HST/STIS observations of the host galaxy
  11. GRB000615: BeppoSAX GRB Alert
  12. The Hosts of GRB 980703 and GRB 971214
  13. GRB 000301C: Further Late-Time HST/STIS observations
  14. GRB000528: follow-up X-ray measurements and update of IPN annulus
  15. Optical Follow-up of GRB000529 Error Box
  16. GRB980519, HST/STIS observations of the host galaxy
  17. GRB000607, Radio Observations
  18. BeppoSAX X-ray transient/possible GRB000608
  19. GRB000604 optical non-detection
  20. GRB000604 - Optical observations
  21. GRB000607, A SHORT, HARD BURST
  22. GRB000604, optical observations
  23. GRB000528, optical observations at ESO
  24. GRB 000604 optical observations
  25. GRB 000418: Detection of the Host Galaxy
  26. GRB000604, optical observations, comparison with DPOSS
  27. GRB000604 [IPN Position]
  28. GRB000528, Radio Observations
  29. X-ray Afterglow of GRB 000529
  30. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  31. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  32. GRB000529: Optical Observations
  33. IPN localization and time history of GRB000528
  34. New IPN localization of GRB000529
  35. GRB000519: Optical observations
  36. IPN localization of GRB000529
  37. GRB 000528 - WFC measurements
  38. GRB000529: BeppoSAX WFC position
  39. GRB000528: BeppoSAX GRBM observations
  40. GRB 000528 Optical Observations
  41. GRB000519, BVRI field photometry
  42. IPN triangulation of GRB000519
  43. IPN triangulation of GRB000516
  44. Re: GRB000508B : Optical observations
  45. GRB 000418, Optical observation
  46. GRB000508B, optical photometry
  47. GRB000508B, BVR field photometry
  48. Possible GRB-related phenomenon
  49. RXTE/ASM and IPN localization of GRB 000508B
  50. GRB000424, UBVRI field photometry
  51. GRB 000424 Optical Observations
  52. GRB000418, UBVRI field photometry update
  53. The redshift of GRB 000418
  54. GRB000424, optical observations
  55. GRB 000429, optical observation
  56. GRB 000429, UBVRI field photometry
  57. IPN localization of GRB000429
  58. GRB 000418, UBVRI field photometry
  59. GRB000418, Radio detection
  60. GRB000418, K'-band photometry
  61. GRB 000418, Optical Observation
  62. GRB 000418, optical observation
  63. GRB000424 Optical Observations
  64. GRB 000418, Optical Observation
  65. GRB000424, optical observations
  66. GRB000424, optical observations
  67. GRB 000424, Optical Observations
  68. GRB 000418, Optical Observation
  69. GRB000418, near-infrared observations
  70. BeppoSAX GRB000424
  71. Correction to IPN error box for GRB000419
  72. IPN error box for GRB000418
  73. GRB000419 [IPN Position]
  74. GRB000416 Optical Observations
  75. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  76. GRB000416 BRJK observations
  77. 1SAXJ1715.0-7134 refined position
  78. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  79. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  80. Budget cuts in BeppoSAX operations: impact on GRB observations
  81. GRB 000408, optical observations
  82. Refined IPN error box for GRB000408
  83. GRB 991208, UBVRI field photometry
  84. GRB000301c results
  85. GRB000408: Optical CCD Observations from MIRO
  86. GRB000408, lotis optical observations
  87. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  88. GRB000408 [IPN Position]
  89. GRB000326 Optical Observations
  90. GRB000301C - Addendum to GCN 623
  91. GRB000301C - R magnitude lower limit
  92. GRB000326, Further VLA observations
  93. GRB 000323, optical observations
  94. GRB 000326: Optical Observations
  95. GRB000326, Radio observations
  96. GRB000326 [IPN Position]
  97. GRB 000307 optical observations
  98. GRB000323 [IPN Position]
  99. Single error box for GRB000315
  100. GRB000315 [IPN Positions]

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