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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"

45440 results found.

  1. GRB 000926: Improved Absorber Redshift
  2. V,R,I band observations of GRB000926
  3. The Likely Optical/Infrared Afterglow of GRB 001011
  4. HETE positions added to GCN
  5. GRB001011 BeppoSAX/WFC refined position
  6. BeppoSAX ALERT: GRB001011
  7. GRB 001007, BVR-band observations
  8. GRB000926 - Amateur Optical Observations
  9. GRB001007: Optical observations
  10. CONCAM null result on GRB001005
  11. IPN triangulation of GRB001007
  12. GRB 000926 : the host galaxy
  13. HETE-2 Launches Successfully
  14. IPN triangulation of GRB001005
  15. HETE-2 48 hour Launch Delay
  16. GRB 000926 Chandra Observation
  17. IPN triangulation of GRB 001004
  18. Public availability of BeppoSAX data of GRB000926
  19. GRB000926: X-ray afterglow by BeppoSAX: revised fluxes (fwd)
  20. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  21. GRB000926 - Optical observations
  22. GRB000926 - Optical observations
  23. GRB 000926, Optical Decay
  24. GRB000911: VLT infrared observation
  25. GRB000926 - Optical observations
  26. GRB000926 - Optical observations
  27. GRB 000926: optical observations
  28. GRB 000926, Optical Observations
  29. GRB000926 - Optical observations
  30. GRB000911: optical VLT observations
  31. GRB000926 K'-band Observation
  32. GRB000926 : increasing optical decay slope
  33. GRB000926 optical observations
  34. GRB000926 - Optical observations
  35. J and K band observations of GRB 000926
  36. GRB000911 Optical Observations
  37. GRB 000926: Lightcurve Update and Predictions
  38. GRB 000926, optical observation by Oksanen (vsnet-grb)
  39. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  40. GRB000926: Optical observations
  41. CONCAM crude optical limits before and after GRB000926
  42. GRB 000926: Preliminary R-band Lightcurve
  43. GRB 000926 HST/Chandra TOO Status
  44. Spectroscopic Redshift of GRB 000926
  45. GRB 000926, Optical Observation
  46. GRB000926, radio observations
  47. GRB 000926: Optical candidate
  48. Optical candidate for GRB000926
  49. IPN triangulation of GRB000926
  50. IPN triangulation of GRB000926
  51. GRB 000911, BVRI field photometry
  52. GRB000911: Corrected coordinates
  53. GRB000911: Sub-millimeter observations
  54. IPN triangulation of GRB000925
  55. GRB000911: Optical Transient
  56. GRB000911, Radio and Optical observations
  57. GRB000911, Radio observations
  58. GRB000911: Optical observations
  59. IPN triangulation of GRB000911
  60. IPN triangulation of GRB000910
  61. False GRB alarm from RXTE/ASM on 8 Sept 2000
  62. GRB 000830: Optical observations
  63. GRB000830: Optical observations
  64. GRB000830, TNG B-band observations
  65. GRB000830, BVRI field photometry
  66. GRB000830: Optical observations
  67. GRB000210, Optical observations
  68. Chandra Position of GRB000210
  69. "Snapshot" afterglow IDs and GRB 000830
  70. GRB000830: Optical observations
  71. IPN triangulation of GRB000830
  72. HST/STIS observations of the host galaxy of GRB 980329
  73. HST/STIS observations of the chaotic environment of GRB 980613
  74. IPN localization of GRB000820
  75. SGR 1806-20 burst activity
  76. GRB000812, TNG R-band observations
  77. GRB000801 & GRB000730, Gamma Ray Observations
  78. GRB000730, Gamma Ray Observations
  79. GRB000812, Radio observations
  80. IPN localization of GRB000812
  81. IPN localization of GRB000811
  82. GRB000801, Gamma Ray Observations
  83. GRB000801, VLT-Antu R-band observations
  84. GRB000301C, UBVI optical observations
  85. GRB000801, Radio Observations
  86. GRB 991208 Host Galaxy Imaging
  87. Updated IPN coordinates for GRB000801
  88. IPN localization of GRB000801
  89. IPN localization of GRB000801
  90. IPN localization of GRB000730B
  91. IPN localization of GRB000730B
  92. IPN localization of GRB000730
  93. GRB 990510: Possible detection of a host galaxy
  94. GRB 990510 Host Galaxy Discovery
  95. GRB 000727, optical observations
  96. IPN localization of GRB000727
  97. GRB 990705, HST/STIS observations of the host galaxy
  98. GRB 990712: Late time HST/STIS Observations
  99. GRB 991216, HST/STIS observations
  100. GRB000620, Radio Observations

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