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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. CONCAM crude optical limits before and after GRB000926
  2. GRB 000926: Preliminary R-band Lightcurve
  3. GRB 000926 HST/Chandra TOO Status
  4. Spectroscopic Redshift of GRB 000926
  5. GRB 000926, Optical Observation
  6. GRB000926, radio observations
  7. GRB 000926: Optical candidate
  8. Optical candidate for GRB000926
  9. IPN triangulation of GRB000926
  10. IPN triangulation of GRB000926
  11. GRB 000911, BVRI field photometry
  12. GRB000911: Corrected coordinates
  13. GRB000911: Sub-millimeter observations
  14. IPN triangulation of GRB000925
  15. GRB000911: Optical Transient
  16. GRB000911, Radio and Optical observations
  17. GRB000911, Radio observations
  18. GRB000911: Optical observations
  19. IPN triangulation of GRB000911
  20. IPN triangulation of GRB000910
  21. False GRB alarm from RXTE/ASM on 8 Sept 2000
  22. GRB 000830: Optical observations
  23. GRB000830: Optical observations
  24. GRB000830, TNG B-band observations
  25. GRB000830, BVRI field photometry
  26. GRB000830: Optical observations
  27. GRB000210, Optical observations
  28. Chandra Position of GRB000210
  29. "Snapshot" afterglow IDs and GRB 000830
  30. GRB000830: Optical observations
  31. IPN triangulation of GRB000830
  32. HST/STIS observations of the host galaxy of GRB 980329
  33. HST/STIS observations of the chaotic environment of GRB 980613
  34. IPN localization of GRB000820
  35. SGR 1806-20 burst activity
  36. GRB000812, TNG R-band observations
  37. GRB000801 & GRB000730, Gamma Ray Observations
  38. GRB000730, Gamma Ray Observations
  39. GRB000812, Radio observations
  40. IPN localization of GRB000812
  41. IPN localization of GRB000811
  42. GRB000801, Gamma Ray Observations
  43. GRB000801, VLT-Antu R-band observations
  44. GRB000301C, UBVI optical observations
  45. GRB000801, Radio Observations
  46. GRB 991208 Host Galaxy Imaging
  47. Updated IPN coordinates for GRB000801
  48. IPN localization of GRB000801
  49. IPN localization of GRB000801
  50. IPN localization of GRB000730B
  51. IPN localization of GRB000730B
  52. IPN localization of GRB000730
  53. GRB 990510: Possible detection of a host galaxy
  54. GRB 990510 Host Galaxy Discovery
  55. GRB 000727, optical observations
  56. IPN localization of GRB000727
  57. GRB 990705, HST/STIS observations of the host galaxy
  58. GRB 990712: Late time HST/STIS Observations
  59. GRB 991216, HST/STIS observations
  60. GRB000620, Radio Observations
  61. GRB981226, HST/STIS observations of the host galaxy
  62. GRB000630, optical observations
  63. GRB 000630: Detection of the Optical Afterglow
  64. GRB000630, Revised BVRI Field Photometry
  65. GRB000630, Optical Observations
  66. GRB000630, optical observations
  67. GRB000630, optical observations
  68. GRB000630, BVRI Field Photometry
  69. GRB000630, optical observations
  70. GRB000630, optical observations
  71. GRB000630: Optical observations
  72. GRB000630, Radio Observations
  73. possible optical counterpart of GRB 000630
  74. IPN triangulation of GRB000630
  75. GRB 000623, optical observations
  76. GRB 000620, optical observations
  77. GRB000418, HST/STIS Observations
  78. GRB990123: Late-time HST/STIS observations of the host
  79. GRB 990506, HST/STIS Observations of the Host Galaxy
  80. GRB000623
  81. GRB 000620: J-band observations
  82. GRB000620, optical observations
  83. GRB000615: H-band observations
  84. GRB990308, HST/STIS observations of the host galaxy
  85. GRB000620 - Optical observations
  86. GRB000620 Optical observations
  87. IPN annulus for GRB000620
  88. GRB000620: BeppoSAX WFC and GRBM detection
  89. GRB000615, Radio observations
  90. GRB000607, optical observations
  91. GRB 000615: NIR further observations
  92. GRB000620: refined BeppoSAX/WFC coordinates
  93. BeppoSAX ALERT: GRB000620
  94. GRB000620: BeppoSAX Alert
  95. GRB990123, HST/STIS observations of the host galaxy
  96. GRB000616 optical observations
  97. GRB 000615, near-infrared observations
  98. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  99. GRB000616 [IPN Position]
  100. GRB000615B [IPN Position]

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