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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"

44350 results found.

  1. IPN TRIANGULATION OF GRB001020
  2. GRB001019, Optical Observations
  3. GRB 001018, Possible Radio Afterglow
  4. GRB001018, Gamma Ray Observations
  5. IPN TRIANGULATION OF GRB001019
  6. CORRECTION TO PEAK FLUX OF GRB001018
  7. IPN TRIANGULATION OF GRB001018
  8. IPN TRIANGULATION OF GRB 001017
  9. GRB 000926: Improved Absorber Redshift
  10. V,R,I band observations of GRB000926
  11. The Likely Optical/Infrared Afterglow of GRB 001011
  12. HETE positions added to GCN
  13. GRB001011 BeppoSAX/WFC refined position
  14. BeppoSAX ALERT: GRB001011
  15. GRB 001007, BVR-band observations
  16. GRB000926 - Amateur Optical Observations
  17. GRB001007: Optical observations
  18. CONCAM null result on GRB001005
  19. IPN triangulation of GRB001007
  20. GRB 000926 : the host galaxy
  21. HETE-2 Launches Successfully
  22. IPN triangulation of GRB001005
  23. HETE-2 48 hour Launch Delay
  24. GRB 000926 Chandra Observation
  25. IPN triangulation of GRB 001004
  26. Public availability of BeppoSAX data of GRB000926
  27. GRB000926: X-ray afterglow by BeppoSAX: revised fluxes (fwd)
  28. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  29. GRB000926 - Optical observations
  30. GRB000926 - Optical observations
  31. GRB 000926, Optical Decay
  32. GRB000911: VLT infrared observation
  33. GRB000926 - Optical observations
  34. GRB000926 - Optical observations
  35. GRB 000926: optical observations
  36. GRB 000926, Optical Observations
  37. GRB000926 - Optical observations
  38. GRB000911: optical VLT observations
  39. GRB000926 K'-band Observation
  40. GRB000926 : increasing optical decay slope
  41. GRB000926 optical observations
  42. GRB000926 - Optical observations
  43. J and K band observations of GRB 000926
  44. GRB000911 Optical Observations
  45. GRB 000926: Lightcurve Update and Predictions
  46. GRB 000926, optical observation by Oksanen (vsnet-grb)
  47. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  48. GRB000926: Optical observations
  49. CONCAM crude optical limits before and after GRB000926
  50. GRB 000926: Preliminary R-band Lightcurve
  51. GRB 000926 HST/Chandra TOO Status
  52. Spectroscopic Redshift of GRB 000926
  53. GRB 000926, Optical Observation
  54. GRB000926, radio observations
  55. GRB 000926: Optical candidate
  56. Optical candidate for GRB000926
  57. IPN triangulation of GRB000926
  58. IPN triangulation of GRB000926
  59. GRB 000911, BVRI field photometry
  60. GRB000911: Corrected coordinates
  61. GRB000911: Sub-millimeter observations
  62. IPN triangulation of GRB000925
  63. GRB000911: Optical Transient
  64. GRB000911, Radio and Optical observations
  65. GRB000911, Radio observations
  66. GRB000911: Optical observations
  67. IPN triangulation of GRB000911
  68. IPN triangulation of GRB000910
  69. False GRB alarm from RXTE/ASM on 8 Sept 2000
  70. GRB 000830: Optical observations
  71. GRB000830: Optical observations
  72. GRB000830, TNG B-band observations
  73. GRB000830, BVRI field photometry
  74. GRB000830: Optical observations
  75. GRB000210, Optical observations
  76. Chandra Position of GRB000210
  77. "Snapshot" afterglow IDs and GRB 000830
  78. GRB000830: Optical observations
  79. IPN triangulation of GRB000830
  80. HST/STIS observations of the host galaxy of GRB 980329
  81. HST/STIS observations of the chaotic environment of GRB 980613
  82. IPN localization of GRB000820
  83. SGR 1806-20 burst activity
  84. GRB000812, TNG R-band observations
  85. GRB000801 & GRB000730, Gamma Ray Observations
  86. GRB000730, Gamma Ray Observations
  87. GRB000812, Radio observations
  88. IPN localization of GRB000812
  89. IPN localization of GRB000811
  90. GRB000801, Gamma Ray Observations
  91. GRB000801, VLT-Antu R-band observations
  92. GRB000301C, UBVI optical observations
  93. GRB000801, Radio Observations
  94. GRB 991208 Host Galaxy Imaging
  95. Updated IPN coordinates for GRB000801
  96. IPN localization of GRB000801
  97. IPN localization of GRB000801
  98. IPN localization of GRB000730B
  99. IPN localization of GRB000730B
  100. IPN localization of GRB000730

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