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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"

42760 results found.

  1. Spectroscopic Redshift of GRB 000926
  2. GRB 000926, Optical Observation
  3. GRB000926, radio observations
  4. GRB 000926: Optical candidate
  5. Optical candidate for GRB000926
  6. IPN triangulation of GRB000926
  7. IPN triangulation of GRB000926
  8. GRB 000911, BVRI field photometry
  9. GRB000911: Sub-millimeter observations
  10. IPN triangulation of GRB000925
  11. GRB000911: Optical Transient
  12. GRB000911, Radio and Optical observations
  13. GRB000911, Radio observations
  14. GRB000911: Optical observations
  15. IPN triangulation of GRB000911
  16. IPN triangulation of GRB000910
  17. False GRB alarm from RXTE/ASM on 8 Sept 2000
  18. GRB 000830: Optical observations
  19. GRB000830: Optical observations
  20. GRB000830, TNG B-band observations
  21. GRB000830, BVRI field photometry
  22. GRB000830: Optical observations
  23. GRB000210, Optical observations
  24. Chandra Position of GRB000210
  25. "Snapshot" afterglow IDs and GRB 000830
  26. GRB000830: Optical observations
  27. IPN triangulation of GRB000830
  28. HST/STIS observations of the host galaxy of GRB 980329
  29. HST/STIS observations of the chaotic environment of GRB 980613
  30. IPN localization of GRB000820
  31. SGR 1806-20 burst activity
  32. GRB000812, TNG R-band observations
  33. GRB000801 & GRB000730, Gamma Ray Observations
  34. GRB000730, Gamma Ray Observations
  35. GRB000812, Radio observations
  36. IPN localization of GRB000812
  37. IPN localization of GRB000811
  38. GRB000801, Gamma Ray Observations
  39. GRB000801, VLT-Antu R-band observations
  40. GRB000301C, UBVI optical observations
  41. GRB000801, Radio Observations
  42. GRB 991208 Host Galaxy Imaging
  43. Updated IPN coordinates for GRB000801
  44. IPN localization of GRB000801
  45. IPN localization of GRB000801
  46. IPN localization of GRB000730B
  47. IPN localization of GRB000730B
  48. IPN localization of GRB000730
  49. GRB 990510: Possible detection of a host galaxy
  50. GRB 990510 Host Galaxy Discovery
  51. GRB 000727, optical observations
  52. IPN localization of GRB000727
  53. GRB 990705, HST/STIS observations of the host galaxy
  54. GRB 990712: Late time HST/STIS Observations
  55. GRB 991216, HST/STIS observations
  56. GRB000620, Radio Observations
  57. GRB981226, HST/STIS observations of the host galaxy
  58. GRB000630, optical observations
  59. GRB 000630: Detection of the Optical Afterglow
  60. GRB000630, Revised BVRI Field Photometry
  61. GRB000630, Optical Observations
  62. GRB000630, optical observations
  63. GRB000630, optical observations
  64. GRB000630, BVRI Field Photometry
  65. GRB000630, optical observations
  66. GRB000630, optical observations
  67. GRB000630: Optical observations
  68. GRB000630, Radio Observations
  69. possible optical counterpart of GRB 000630
  70. IPN triangulation of GRB000630
  71. GRB 000623, optical observations
  72. GRB 000620, optical observations
  73. GRB000418, HST/STIS Observations
  74. GRB990123: Late-time HST/STIS observations of the host
  75. GRB 990506, HST/STIS Observations of the Host Galaxy
  76. GRB000623
  77. GRB 000620: J-band observations
  78. GRB000620, optical observations
  79. GRB000615: H-band observations
  80. GRB990308, HST/STIS observations of the host galaxy
  81. GRB000620 - Optical observations
  82. GRB000620 Optical observations
  83. IPN annulus for GRB000620
  84. GRB000620: BeppoSAX WFC and GRBM detection
  85. GRB000615, Radio observations
  86. GRB000607, optical observations
  87. GRB 000615: NIR further observations
  88. BeppoSAX ALERT: GRB000620
  89. GRB000620: BeppoSAX Alert
  90. GRB990123, HST/STIS observations of the host galaxy
  91. GRB000616 optical observations
  92. GRB 000615, near-infrared observations
  93. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  94. GRB000616 [IPN Position]
  95. GRB000615B [IPN Position]
  96. GRB000615, further R-band photometry
  97. GRB 000615: NIR observations
  98. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  99. GRB000615, R-band photometry
  100. GRB980425, HST/STIS observations of the host galaxy

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