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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. GRB000630, optical observations
  2. GRB000630: Optical observations
  3. GRB000630, Radio Observations
  4. possible optical counterpart of GRB 000630
  5. IPN triangulation of GRB000630
  6. GRB 000623, optical observations
  7. GRB 000620, optical observations
  8. GRB000418, HST/STIS Observations
  9. GRB990123: Late-time HST/STIS observations of the host
  10. GRB 990506, HST/STIS Observations of the Host Galaxy
  11. GRB000623
  12. GRB 000620: J-band observations
  13. GRB000620, optical observations
  14. GRB000615: H-band observations
  15. GRB990308, HST/STIS observations of the host galaxy
  16. GRB000620 - Optical observations
  17. GRB000620 Optical observations
  18. IPN annulus for GRB000620
  19. GRB000620: BeppoSAX WFC and GRBM detection
  20. GRB000615, Radio observations
  21. GRB000607, optical observations
  22. GRB 000615: NIR further observations
  23. GRB000620: refined BeppoSAX/WFC coordinates
  24. BeppoSAX ALERT: GRB000620
  25. GRB000620: BeppoSAX Alert
  26. GRB990123, HST/STIS observations of the host galaxy
  27. GRB000616 optical observations
  28. GRB 000615, near-infrared observations
  29. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  30. GRB000616 [IPN Position]
  31. GRB000615B [IPN Position]
  32. GRB000615, further R-band photometry
  33. GRB 000615: NIR observations
  34. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  35. GRB000615, R-band photometry
  36. GRB000615: BeppoSAX refined coordinates
  37. GRB980425, HST/STIS observations of the host galaxy
  38. GRB000615: BeppoSAX GRB Alert
  39. The Hosts of GRB 980703 and GRB 971214
  40. GRB 000301C: Further Late-Time HST/STIS observations
  41. GRB000528: follow-up X-ray measurements and update of IPN annulus
  42. Optical Follow-up of GRB000529 Error Box
  43. GRB980519, HST/STIS observations of the host galaxy
  44. GRB000607, Radio Observations
  45. BeppoSAX X-ray transient/possible GRB000608
  46. GRB000604 optical non-detection
  47. GRB000604 - Optical observations
  48. GRB000607, A SHORT, HARD BURST
  49. GRB000604, optical observations
  50. GRB000528, optical observations at ESO
  51. GRB 000604 optical observations
  52. GRB 000418: Detection of the Host Galaxy
  53. GRB000604, optical observations, comparison with DPOSS
  54. GRB000604 [IPN Position]
  55. GRB000528, Radio Observations
  56. X-ray Afterglow of GRB 000529
  57. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  58. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  59. GRB000529: Optical Observations
  60. IPN localization and time history of GRB000528
  61. New IPN localization of GRB000529
  62. GRB000519: Optical observations
  63. IPN localization of GRB000529
  64. GRB 000528 - WFC measurements
  65. GRB000529: BeppoSAX WFC position
  66. GRB000528: BeppoSAX GRBM observations
  67. GRB 000528 Optical Observations
  68. GRB000519, BVRI field photometry
  69. IPN triangulation of GRB000519
  70. IPN triangulation of GRB000516
  71. Re: GRB000508B : Optical observations
  72. GRB 000418, Optical observation
  73. GRB000508B, optical photometry
  74. GRB000508B, BVR field photometry
  75. Possible GRB-related phenomenon
  76. RXTE/ASM and IPN localization of GRB 000508B
  77. GRB000424, UBVRI field photometry
  78. GRB 000424 Optical Observations
  79. GRB000418, UBVRI field photometry update
  80. The redshift of GRB 000418
  81. GRB000424, optical observations
  82. GRB 000429, optical observation
  83. GRB 000429, UBVRI field photometry
  84. IPN localization of GRB000429
  85. GRB 000418, UBVRI field photometry
  86. GRB000418, Radio detection
  87. GRB000418, K'-band photometry
  88. GRB 000418, Optical Observation
  89. GRB 000418, optical observation
  90. GRB000424 Optical Observations
  91. GRB 000418, Optical Observation
  92. GRB000424, optical observations
  93. GRB000424, optical observations
  94. GRB 000424, Optical Observations
  95. GRB 000418, Optical Observation
  96. GRB000418, near-infrared observations
  97. BeppoSAX GRB000424
  98. Correction to IPN error box for GRB000419
  99. IPN error box for GRB000418
  100. GRB000419 [IPN Position]

Advanced

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