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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. GRB000911, Radio observations
  2. GRB000911: Optical observations
  3. IPN triangulation of GRB000911
  4. IPN triangulation of GRB000910
  5. False GRB alarm from RXTE/ASM on 8 Sept 2000
  6. GRB 000830: Optical observations
  7. GRB000830: Optical observations
  8. GRB000830, TNG B-band observations
  9. GRB000830, BVRI field photometry
  10. GRB000830: Optical observations
  11. GRB000210, Optical observations
  12. Chandra Position of GRB000210
  13. "Snapshot" afterglow IDs and GRB 000830
  14. GRB000830: Optical observations
  15. IPN triangulation of GRB000830
  16. HST/STIS observations of the host galaxy of GRB 980329
  17. HST/STIS observations of the chaotic environment of GRB 980613
  18. IPN localization of GRB000820
  19. SGR 1806-20 burst activity
  20. GRB000812, TNG R-band observations
  21. GRB000801 & GRB000730, Gamma Ray Observations
  22. GRB000730, Gamma Ray Observations
  23. GRB000812, Radio observations
  24. IPN localization of GRB000812
  25. IPN localization of GRB000811
  26. GRB000801, Gamma Ray Observations
  27. GRB000801, VLT-Antu R-band observations
  28. GRB000301C, UBVI optical observations
  29. GRB000801, Radio Observations
  30. GRB 991208 Host Galaxy Imaging
  31. Updated IPN coordinates for GRB000801
  32. IPN localization of GRB000801
  33. IPN localization of GRB000801
  34. IPN localization of GRB000730B
  35. IPN localization of GRB000730B
  36. IPN localization of GRB000730
  37. GRB 990510: Possible detection of a host galaxy
  38. GRB 990510 Host Galaxy Discovery
  39. GRB 000727, optical observations
  40. IPN localization of GRB000727
  41. GRB 990705, HST/STIS observations of the host galaxy
  42. GRB 990712: Late time HST/STIS Observations
  43. GRB 991216, HST/STIS observations
  44. GRB000620, Radio Observations
  45. GRB981226, HST/STIS observations of the host galaxy
  46. GRB000630, optical observations
  47. GRB 000630: Detection of the Optical Afterglow
  48. GRB000630, Revised BVRI Field Photometry
  49. GRB000630, Optical Observations
  50. GRB000630, optical observations
  51. GRB000630, optical observations
  52. GRB000630, BVRI Field Photometry
  53. GRB000630, optical observations
  54. GRB000630, optical observations
  55. GRB000630: Optical observations
  56. GRB000630, Radio Observations
  57. possible optical counterpart of GRB 000630
  58. IPN triangulation of GRB000630
  59. GRB 000623, optical observations
  60. GRB 000620, optical observations
  61. GRB000418, HST/STIS Observations
  62. GRB990123: Late-time HST/STIS observations of the host
  63. GRB 990506, HST/STIS Observations of the Host Galaxy
  64. GRB000623
  65. GRB 000620: J-band observations
  66. GRB000620, optical observations
  67. GRB000615: H-band observations
  68. GRB990308, HST/STIS observations of the host galaxy
  69. GRB000620 - Optical observations
  70. GRB000620 Optical observations
  71. IPN annulus for GRB000620
  72. GRB000620: BeppoSAX WFC and GRBM detection
  73. GRB000615, Radio observations
  74. GRB000607, optical observations
  75. GRB 000615: NIR further observations
  76. GRB000620: refined BeppoSAX/WFC coordinates
  77. BeppoSAX ALERT: GRB000620
  78. GRB000620: BeppoSAX Alert
  79. GRB990123, HST/STIS observations of the host galaxy
  80. GRB000616 optical observations
  81. GRB 000615, near-infrared observations
  82. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  83. GRB000616 [IPN Position]
  84. GRB000615B [IPN Position]
  85. GRB000615, further R-band photometry
  86. GRB 000615: NIR observations
  87. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  88. GRB000615, R-band photometry
  89. GRB000615: BeppoSAX refined coordinates
  90. GRB980425, HST/STIS observations of the host galaxy
  91. GRB000615: BeppoSAX GRB Alert
  92. The Hosts of GRB 980703 and GRB 971214
  93. GRB 000301C: Further Late-Time HST/STIS observations
  94. GRB000528: follow-up X-ray measurements and update of IPN annulus
  95. Optical Follow-up of GRB000529 Error Box
  96. GRB980519, HST/STIS observations of the host galaxy
  97. GRB000607, Radio Observations
  98. BeppoSAX X-ray transient/possible GRB000608
  99. GRB000604 optical non-detection
  100. GRB000604 - Optical observations

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