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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"
  1. IPN localization of GRB000727
  2. GRB 990705, HST/STIS observations of the host galaxy
  3. GRB 990712: Late time HST/STIS Observations
  4. GRB 991216, HST/STIS observations
  5. GRB000620, Radio Observations
  6. GRB981226, HST/STIS observations of the host galaxy
  7. GRB000630, optical observations
  8. GRB 000630: Detection of the Optical Afterglow
  9. GRB000630, Revised BVRI Field Photometry
  10. GRB000630, Optical Observations
  11. GRB000630, optical observations
  12. GRB000630, optical observations
  13. GRB000630, BVRI Field Photometry
  14. GRB000630, optical observations
  15. GRB000630, optical observations
  16. GRB000630: Optical observations
  17. GRB000630, Radio Observations
  18. possible optical counterpart of GRB 000630
  19. IPN triangulation of GRB000630
  20. GRB 000623, optical observations
  21. GRB 000620, optical observations
  22. GRB000418, HST/STIS Observations
  23. GRB990123: Late-time HST/STIS observations of the host
  24. GRB 990506, HST/STIS Observations of the Host Galaxy
  25. GRB000623
  26. GRB 000620: J-band observations
  27. GRB000620, optical observations
  28. GRB000615: H-band observations
  29. GRB990308, HST/STIS observations of the host galaxy
  30. GRB000620 - Optical observations
  31. GRB000620 Optical observations
  32. IPN annulus for GRB000620
  33. GRB000620: BeppoSAX WFC and GRBM detection
  34. GRB000615, Radio observations
  35. GRB000607, optical observations
  36. GRB 000615: NIR further observations
  37. GRB000620: refined BeppoSAX/WFC coordinates
  38. BeppoSAX ALERT: GRB000620
  39. GRB000620: BeppoSAX Alert
  40. GRB990123, HST/STIS observations of the host galaxy
  41. GRB000616 optical observations
  42. GRB 000615, near-infrared observations
  43. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  44. GRB000616 [IPN Position]
  45. GRB000615B [IPN Position]
  46. GRB000615, further R-band photometry
  47. GRB 000615: NIR observations
  48. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  49. GRB000615, R-band photometry
  50. GRB000615: BeppoSAX refined coordinates
  51. GRB980425, HST/STIS observations of the host galaxy
  52. GRB000615: BeppoSAX GRB Alert
  53. The Hosts of GRB 980703 and GRB 971214
  54. GRB 000301C: Further Late-Time HST/STIS observations
  55. GRB000528: follow-up X-ray measurements and update of IPN annulus
  56. Optical Follow-up of GRB000529 Error Box
  57. GRB980519, HST/STIS observations of the host galaxy
  58. GRB000607, Radio Observations
  59. BeppoSAX X-ray transient/possible GRB000608
  60. GRB000604 optical non-detection
  61. GRB000604 - Optical observations
  62. GRB000607, A SHORT, HARD BURST
  63. GRB000604, optical observations
  64. GRB000528, optical observations at ESO
  65. GRB 000604 optical observations
  66. GRB 000418: Detection of the Host Galaxy
  67. GRB000604, optical observations, comparison with DPOSS
  68. GRB000604 [IPN Position]
  69. GRB000528, Radio Observations
  70. X-ray Afterglow of GRB 000529
  71. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  72. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  73. GRB000529: Optical Observations
  74. IPN localization and time history of GRB000528
  75. New IPN localization of GRB000529
  76. GRB000519: Optical observations
  77. IPN localization of GRB000529
  78. GRB 000528 - WFC measurements
  79. GRB000529: BeppoSAX WFC position
  80. GRB000528: BeppoSAX GRBM observations
  81. GRB 000528 Optical Observations
  82. GRB000519, BVRI field photometry
  83. IPN triangulation of GRB000519
  84. IPN triangulation of GRB000516
  85. Re: GRB000508B : Optical observations
  86. GRB 000418, Optical observation
  87. GRB000508B, optical photometry
  88. GRB000508B, BVR field photometry
  89. Possible GRB-related phenomenon
  90. RXTE/ASM and IPN localization of GRB 000508B
  91. GRB000424, UBVRI field photometry
  92. GRB 000424 Optical Observations
  93. GRB000418, UBVRI field photometry update
  94. The redshift of GRB 000418
  95. GRB000424, optical observations
  96. GRB 000429, optical observation
  97. GRB 000429, UBVRI field photometry
  98. IPN localization of GRB000429
  99. GRB 000418, UBVRI field photometry
  100. GRB000418, Radio detection

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