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

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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