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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. IPN annulus for GRB000620
  2. GRB000620: BeppoSAX WFC and GRBM detection
  3. GRB000615, Radio observations
  4. GRB000607, optical observations
  5. GRB 000615: NIR further observations
  6. GRB000620: refined BeppoSAX/WFC coordinates
  7. BeppoSAX ALERT: GRB000620
  8. GRB000620: BeppoSAX Alert
  9. GRB990123, HST/STIS observations of the host galaxy
  10. GRB000616 optical observations
  11. GRB 000615, near-infrared observations
  12. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  13. GRB000616 [IPN Position]
  14. GRB000615B [IPN Position]
  15. GRB000615, further R-band photometry
  16. GRB 000615: NIR observations
  17. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  18. GRB000615, R-band photometry
  19. GRB000615: BeppoSAX refined coordinates
  20. GRB980425, HST/STIS observations of the host galaxy
  21. GRB000615: BeppoSAX GRB Alert
  22. The Hosts of GRB 980703 and GRB 971214
  23. GRB 000301C: Further Late-Time HST/STIS observations
  24. GRB000528: follow-up X-ray measurements and update of IPN annulus
  25. Optical Follow-up of GRB000529 Error Box
  26. GRB980519, HST/STIS observations of the host galaxy
  27. GRB000607, Radio Observations
  28. BeppoSAX X-ray transient/possible GRB000608
  29. GRB000604 optical non-detection
  30. GRB000604 - Optical observations
  31. GRB000607, A SHORT, HARD BURST
  32. GRB000604, optical observations
  33. GRB000528, optical observations at ESO
  34. GRB 000604 optical observations
  35. GRB 000418: Detection of the Host Galaxy
  36. GRB000604, optical observations, comparison with DPOSS
  37. GRB000604 [IPN Position]
  38. GRB000528, Radio Observations
  39. X-ray Afterglow of GRB 000529
  40. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  41. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  42. GRB000529: Optical Observations
  43. IPN localization and time history of GRB000528
  44. New IPN localization of GRB000529
  45. GRB000519: Optical observations
  46. IPN localization of GRB000529
  47. GRB 000528 - WFC measurements
  48. GRB000529: BeppoSAX WFC position
  49. GRB000528: BeppoSAX GRBM observations
  50. GRB 000528 Optical Observations
  51. GRB000519, BVRI field photometry
  52. IPN triangulation of GRB000519
  53. IPN triangulation of GRB000516
  54. Re: GRB000508B : Optical observations
  55. GRB 000418, Optical observation
  56. GRB000508B, optical photometry
  57. GRB000508B, BVR field photometry
  58. Possible GRB-related phenomenon
  59. RXTE/ASM and IPN localization of GRB 000508B
  60. GRB000424, UBVRI field photometry
  61. GRB 000424 Optical Observations
  62. GRB000418, UBVRI field photometry update
  63. The redshift of GRB 000418
  64. GRB000424, optical observations
  65. GRB 000429, optical observation
  66. GRB 000429, UBVRI field photometry
  67. IPN localization of GRB000429
  68. GRB 000418, UBVRI field photometry
  69. GRB000418, Radio detection
  70. GRB000418, K'-band photometry
  71. GRB 000418, Optical Observation
  72. GRB 000418, optical observation
  73. GRB000424 Optical Observations
  74. GRB 000418, Optical Observation
  75. GRB000424, optical observations
  76. GRB000424, optical observations
  77. GRB 000424, Optical Observations
  78. GRB 000418, Optical Observation
  79. GRB000418, near-infrared observations
  80. BeppoSAX GRB000424
  81. Correction to IPN error box for GRB000419
  82. IPN error box for GRB000418
  83. GRB000419 [IPN Position]
  84. GRB000416 Optical Observations
  85. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  86. GRB000416 BRJK observations
  87. 1SAXJ1715.0-7134 refined position
  88. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  89. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  90. Budget cuts in BeppoSAX operations: impact on GRB observations
  91. GRB 000408, optical observations
  92. Refined IPN error box for GRB000408
  93. GRB 991208, UBVRI field photometry
  94. GRB000301c results
  95. GRB000408: Optical CCD Observations from MIRO
  96. GRB000408, lotis optical observations
  97. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  98. GRB000408 [IPN Position]
  99. GRB000326 Optical Observations
  100. GRB000301C - Addendum to GCN 623

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