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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 GRB000812
  2. IPN localization of GRB000811
  3. GRB000801, Gamma Ray Observations
  4. GRB000801, VLT-Antu R-band observations
  5. GRB000301C, UBVI optical observations
  6. GRB000801, Radio Observations
  7. GRB 991208 Host Galaxy Imaging
  8. Updated IPN coordinates for GRB000801
  9. IPN localization of GRB000801
  10. IPN localization of GRB000801
  11. IPN localization of GRB000730B
  12. IPN localization of GRB000730B
  13. IPN localization of GRB000730
  14. GRB 990510: Possible detection of a host galaxy
  15. GRB 990510 Host Galaxy Discovery
  16. GRB 000727, optical observations
  17. IPN localization of GRB000727
  18. GRB 990705, HST/STIS observations of the host galaxy
  19. GRB 990712: Late time HST/STIS Observations
  20. GRB 991216, HST/STIS observations
  21. GRB000620, Radio Observations
  22. GRB981226, HST/STIS observations of the host galaxy
  23. GRB000630, optical observations
  24. GRB 000630: Detection of the Optical Afterglow
  25. GRB000630, Revised BVRI Field Photometry
  26. GRB000630, Optical Observations
  27. GRB000630, optical observations
  28. GRB000630, optical observations
  29. GRB000630, BVRI Field Photometry
  30. GRB000630, optical observations
  31. GRB000630, optical observations
  32. GRB000630: Optical observations
  33. GRB000630, Radio Observations
  34. possible optical counterpart of GRB 000630
  35. IPN triangulation of GRB000630
  36. GRB 000623, optical observations
  37. GRB 000620, optical observations
  38. GRB000418, HST/STIS Observations
  39. GRB990123: Late-time HST/STIS observations of the host
  40. GRB 990506, HST/STIS Observations of the Host Galaxy
  41. GRB000623
  42. GRB 000620: J-band observations
  43. GRB000620, optical observations
  44. GRB000615: H-band observations
  45. GRB990308, HST/STIS observations of the host galaxy
  46. GRB000620 - Optical observations
  47. GRB000620 Optical observations
  48. IPN annulus for GRB000620
  49. GRB000620: BeppoSAX WFC and GRBM detection
  50. GRB000615, Radio observations
  51. GRB000607, optical observations
  52. GRB 000615: NIR further observations
  53. GRB000620: refined BeppoSAX/WFC coordinates
  54. BeppoSAX ALERT: GRB000620
  55. GRB000620: BeppoSAX Alert
  56. GRB990123, HST/STIS observations of the host galaxy
  57. GRB000616 optical observations
  58. GRB 000615, near-infrared observations
  59. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  60. GRB000616 [IPN Position]
  61. GRB000615B [IPN Position]
  62. GRB000615, further R-band photometry
  63. GRB 000615: NIR observations
  64. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  65. GRB000615, R-band photometry
  66. GRB000615: BeppoSAX refined coordinates
  67. GRB980425, HST/STIS observations of the host galaxy
  68. GRB000615: BeppoSAX GRB Alert
  69. The Hosts of GRB 980703 and GRB 971214
  70. GRB 000301C: Further Late-Time HST/STIS observations
  71. GRB000528: follow-up X-ray measurements and update of IPN annulus
  72. Optical Follow-up of GRB000529 Error Box
  73. GRB980519, HST/STIS observations of the host galaxy
  74. GRB000607, Radio Observations
  75. BeppoSAX X-ray transient/possible GRB000608
  76. GRB000604 optical non-detection
  77. GRB000604 - Optical observations
  78. GRB000607, A SHORT, HARD BURST
  79. GRB000604, optical observations
  80. GRB000528, optical observations at ESO
  81. GRB 000604 optical observations
  82. GRB 000418: Detection of the Host Galaxy
  83. GRB000604, optical observations, comparison with DPOSS
  84. GRB000604 [IPN Position]
  85. GRB000528, Radio Observations
  86. X-ray Afterglow of GRB 000529
  87. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  88. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  89. GRB000529: Optical Observations
  90. IPN localization and time history of GRB000528
  91. New IPN localization of GRB000529
  92. GRB000519: Optical observations
  93. IPN localization of GRB000529
  94. GRB 000528 - WFC measurements
  95. GRB000529: BeppoSAX WFC position
  96. GRB000528: BeppoSAX GRBM observations
  97. GRB 000528 Optical Observations
  98. GRB000519, BVRI field photometry
  99. IPN triangulation of GRB000519
  100. IPN triangulation of GRB000516

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