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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 GRB000801
  2. IPN localization of GRB000801
  3. IPN localization of GRB000730B
  4. IPN localization of GRB000730B
  5. IPN localization of GRB000730
  6. GRB 990510: Possible detection of a host galaxy
  7. GRB 990510 Host Galaxy Discovery
  8. GRB 000727, optical observations
  9. IPN localization of GRB000727
  10. GRB 990705, HST/STIS observations of the host galaxy
  11. GRB 990712: Late time HST/STIS Observations
  12. GRB 991216, HST/STIS observations
  13. GRB000620, Radio Observations
  14. GRB981226, HST/STIS observations of the host galaxy
  15. GRB000630, optical observations
  16. GRB 000630: Detection of the Optical Afterglow
  17. GRB000630, Revised BVRI Field Photometry
  18. GRB000630, Optical Observations
  19. GRB000630, optical observations
  20. GRB000630, optical observations
  21. GRB000630, BVRI Field Photometry
  22. GRB000630, optical observations
  23. GRB000630, optical observations
  24. GRB000630: Optical observations
  25. GRB000630, Radio Observations
  26. possible optical counterpart of GRB 000630
  27. IPN triangulation of GRB000630
  28. GRB 000623, optical observations
  29. GRB 000620, optical observations
  30. GRB000418, HST/STIS Observations
  31. GRB990123: Late-time HST/STIS observations of the host
  32. GRB 990506, HST/STIS Observations of the Host Galaxy
  33. GRB000623
  34. GRB 000620: J-band observations
  35. GRB000620, optical observations
  36. GRB000615: H-band observations
  37. GRB990308, HST/STIS observations of the host galaxy
  38. GRB000620 - Optical observations
  39. GRB000620 Optical observations
  40. IPN annulus for GRB000620
  41. GRB000620: BeppoSAX WFC and GRBM detection
  42. GRB000615, Radio observations
  43. GRB000607, optical observations
  44. GRB 000615: NIR further observations
  45. GRB000620: refined BeppoSAX/WFC coordinates
  46. BeppoSAX ALERT: GRB000620
  47. GRB000620: BeppoSAX Alert
  48. GRB990123, HST/STIS observations of the host galaxy
  49. GRB000616 optical observations
  50. GRB 000615, near-infrared observations
  51. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  52. GRB000616 [IPN Position]
  53. GRB000615B [IPN Position]
  54. GRB000615, further R-band photometry
  55. GRB 000615: NIR observations
  56. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  57. GRB000615, R-band photometry
  58. GRB000615: BeppoSAX refined coordinates
  59. GRB980425, HST/STIS observations of the host galaxy
  60. GRB000615: BeppoSAX GRB Alert
  61. The Hosts of GRB 980703 and GRB 971214
  62. GRB 000301C: Further Late-Time HST/STIS observations
  63. GRB000528: follow-up X-ray measurements and update of IPN annulus
  64. Optical Follow-up of GRB000529 Error Box
  65. GRB980519, HST/STIS observations of the host galaxy
  66. GRB000607, Radio Observations
  67. BeppoSAX X-ray transient/possible GRB000608
  68. GRB000604 optical non-detection
  69. GRB000604 - Optical observations
  70. GRB000607, A SHORT, HARD BURST
  71. GRB000604, optical observations
  72. GRB000528, optical observations at ESO
  73. GRB 000604 optical observations
  74. GRB 000418: Detection of the Host Galaxy
  75. GRB000604, optical observations, comparison with DPOSS
  76. GRB000604 [IPN Position]
  77. GRB000528, Radio Observations
  78. X-ray Afterglow of GRB 000529
  79. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  80. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  81. GRB000529: Optical Observations
  82. IPN localization and time history of GRB000528
  83. New IPN localization of GRB000529
  84. GRB000519: Optical observations
  85. IPN localization of GRB000529
  86. GRB 000528 - WFC measurements
  87. GRB000529: BeppoSAX WFC position
  88. GRB000528: BeppoSAX GRBM observations
  89. GRB 000528 Optical Observations
  90. GRB000519, BVRI field photometry
  91. IPN triangulation of GRB000519
  92. IPN triangulation of GRB000516
  93. Re: GRB000508B : Optical observations
  94. GRB 000418, Optical observation
  95. GRB000508B, optical photometry
  96. GRB000508B, BVR field photometry
  97. Possible GRB-related phenomenon
  98. RXTE/ASM and IPN localization of GRB 000508B
  99. GRB000424, UBVRI field photometry
  100. GRB 000424 Optical Observations

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