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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"

45446 results found.

  1. IPN TRIANGULATION OF GRB001019
  2. CORRECTION TO PEAK FLUX OF GRB001018
  3. IPN TRIANGULATION OF GRB001018
  4. IPN TRIANGULATION OF GRB 001017
  5. GRB 000926: Improved Absorber Redshift
  6. V,R,I band observations of GRB000926
  7. The Likely Optical/Infrared Afterglow of GRB 001011
  8. HETE positions added to GCN
  9. GRB001011 BeppoSAX/WFC refined position
  10. BeppoSAX ALERT: GRB001011
  11. GRB 001007, BVR-band observations
  12. GRB000926 - Amateur Optical Observations
  13. GRB001007: Optical observations
  14. CONCAM null result on GRB001005
  15. IPN triangulation of GRB001007
  16. GRB 000926 : the host galaxy
  17. HETE-2 Launches Successfully
  18. IPN triangulation of GRB001005
  19. HETE-2 48 hour Launch Delay
  20. GRB 000926 Chandra Observation
  21. IPN triangulation of GRB 001004
  22. Public availability of BeppoSAX data of GRB000926
  23. GRB000926: X-ray afterglow by BeppoSAX: revised fluxes (fwd)
  24. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  25. GRB000926 - Optical observations
  26. GRB000926 - Optical observations
  27. GRB 000926, Optical Decay
  28. GRB000911: VLT infrared observation
  29. GRB000926 - Optical observations
  30. GRB000926 - Optical observations
  31. GRB 000926: optical observations
  32. GRB 000926, Optical Observations
  33. GRB000926 - Optical observations
  34. GRB000911: optical VLT observations
  35. GRB000926 K'-band Observation
  36. GRB000926 : increasing optical decay slope
  37. GRB000926 optical observations
  38. GRB000926 - Optical observations
  39. J and K band observations of GRB 000926
  40. GRB000911 Optical Observations
  41. GRB 000926: Lightcurve Update and Predictions
  42. GRB 000926, optical observation by Oksanen (vsnet-grb)
  43. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  44. GRB000926: Optical observations
  45. CONCAM crude optical limits before and after GRB000926
  46. GRB 000926: Preliminary R-band Lightcurve
  47. GRB 000926 HST/Chandra TOO Status
  48. Spectroscopic Redshift of GRB 000926
  49. GRB 000926, Optical Observation
  50. GRB000926, radio observations
  51. GRB 000926: Optical candidate
  52. Optical candidate for GRB000926
  53. IPN triangulation of GRB000926
  54. IPN triangulation of GRB000926
  55. GRB 000911, BVRI field photometry
  56. GRB000911: Corrected coordinates
  57. GRB000911: Sub-millimeter observations
  58. IPN triangulation of GRB000925
  59. GRB000911: Optical Transient
  60. GRB000911, Radio and Optical observations
  61. GRB000911, Radio observations
  62. GRB000911: Optical observations
  63. IPN triangulation of GRB000911
  64. IPN triangulation of GRB000910
  65. False GRB alarm from RXTE/ASM on 8 Sept 2000
  66. GRB 000830: Optical observations
  67. GRB000830: Optical observations
  68. GRB000830, TNG B-band observations
  69. GRB000830, BVRI field photometry
  70. GRB000830: Optical observations
  71. GRB000210, Optical observations
  72. Chandra Position of GRB000210
  73. "Snapshot" afterglow IDs and GRB 000830
  74. GRB000830: Optical observations
  75. IPN triangulation of GRB000830
  76. HST/STIS observations of the host galaxy of GRB 980329
  77. HST/STIS observations of the chaotic environment of GRB 980613
  78. IPN localization of GRB000820
  79. SGR 1806-20 burst activity
  80. GRB000812, TNG R-band observations
  81. GRB000801 & GRB000730, Gamma Ray Observations
  82. GRB000730, Gamma Ray Observations
  83. GRB000812, Radio observations
  84. IPN localization of GRB000812
  85. IPN localization of GRB000811
  86. GRB000801, Gamma Ray Observations
  87. GRB000801, VLT-Antu R-band observations
  88. GRB000301C, UBVI optical observations
  89. GRB000801, Radio Observations
  90. GRB 991208 Host Galaxy Imaging
  91. Updated IPN coordinates for GRB000801
  92. IPN localization of GRB000801
  93. IPN localization of GRB000801
  94. IPN localization of GRB000730B
  95. IPN localization of GRB000730B
  96. IPN localization of GRB000730
  97. GRB 990510: Possible detection of a host galaxy
  98. GRB 990510 Host Galaxy Discovery
  99. GRB 000727, optical observations
  100. IPN localization of GRB000727

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