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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"

45450 results found.

  1. ASM Localization of GRB 001025
  2. GRB001007, Radio observations
  3. IPN TRIANGULATION OF GRB001020
  4. GRB001019, Optical Observations
  5. GRB 001018, Possible Radio Afterglow
  6. GRB001018, Gamma Ray Observations
  7. IPN TRIANGULATION OF GRB001019
  8. CORRECTION TO PEAK FLUX OF GRB001018
  9. IPN TRIANGULATION OF GRB001018
  10. IPN TRIANGULATION OF GRB 001017
  11. GRB 000926: Improved Absorber Redshift
  12. V,R,I band observations of GRB000926
  13. The Likely Optical/Infrared Afterglow of GRB 001011
  14. HETE positions added to GCN
  15. GRB001011 BeppoSAX/WFC refined position
  16. BeppoSAX ALERT: GRB001011
  17. GRB 001007, BVR-band observations
  18. GRB000926 - Amateur Optical Observations
  19. GRB001007: Optical observations
  20. CONCAM null result on GRB001005
  21. IPN triangulation of GRB001007
  22. GRB 000926 : the host galaxy
  23. HETE-2 Launches Successfully
  24. IPN triangulation of GRB001005
  25. HETE-2 48 hour Launch Delay
  26. GRB 000926 Chandra Observation
  27. IPN triangulation of GRB 001004
  28. Public availability of BeppoSAX data of GRB000926
  29. GRB000926: X-ray afterglow by BeppoSAX: revised fluxes (fwd)
  30. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  31. GRB000926 - Optical observations
  32. GRB000926 - Optical observations
  33. GRB 000926, Optical Decay
  34. GRB000911: VLT infrared observation
  35. GRB000926 - Optical observations
  36. GRB000926 - Optical observations
  37. GRB 000926: optical observations
  38. GRB 000926, Optical Observations
  39. GRB000926 - Optical observations
  40. GRB000911: optical VLT observations
  41. GRB000926 K'-band Observation
  42. GRB000926 : increasing optical decay slope
  43. GRB000926 optical observations
  44. GRB000926 - Optical observations
  45. J and K band observations of GRB 000926
  46. GRB000911 Optical Observations
  47. GRB 000926: Lightcurve Update and Predictions
  48. GRB 000926, optical observation by Oksanen (vsnet-grb)
  49. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  50. GRB000926: Optical observations
  51. CONCAM crude optical limits before and after GRB000926
  52. GRB 000926: Preliminary R-band Lightcurve
  53. GRB 000926 HST/Chandra TOO Status
  54. Spectroscopic Redshift of GRB 000926
  55. GRB 000926, Optical Observation
  56. GRB000926, radio observations
  57. GRB 000926: Optical candidate
  58. Optical candidate for GRB000926
  59. IPN triangulation of GRB000926
  60. IPN triangulation of GRB000926
  61. GRB 000911, BVRI field photometry
  62. GRB000911: Corrected coordinates
  63. GRB000911: Sub-millimeter observations
  64. IPN triangulation of GRB000925
  65. GRB000911: Optical Transient
  66. GRB000911, Radio and Optical observations
  67. GRB000911, Radio observations
  68. GRB000911: Optical observations
  69. IPN triangulation of GRB000911
  70. IPN triangulation of GRB000910
  71. False GRB alarm from RXTE/ASM on 8 Sept 2000
  72. GRB 000830: Optical observations
  73. GRB000830: Optical observations
  74. GRB000830, TNG B-band observations
  75. GRB000830, BVRI field photometry
  76. GRB000830: Optical observations
  77. GRB000210, Optical observations
  78. Chandra Position of GRB000210
  79. "Snapshot" afterglow IDs and GRB 000830
  80. GRB000830: Optical observations
  81. IPN triangulation of GRB000830
  82. HST/STIS observations of the host galaxy of GRB 980329
  83. HST/STIS observations of the chaotic environment of GRB 980613
  84. IPN localization of GRB000820
  85. SGR 1806-20 burst activity
  86. GRB000812, TNG R-band observations
  87. GRB000801 & GRB000730, Gamma Ray Observations
  88. GRB000730, Gamma Ray Observations
  89. GRB000812, Radio observations
  90. IPN localization of GRB000812
  91. IPN localization of GRB000811
  92. GRB000801, Gamma Ray Observations
  93. GRB000801, VLT-Antu R-band observations
  94. GRB000301C, UBVI optical observations
  95. GRB000801, Radio Observations
  96. GRB 991208 Host Galaxy Imaging
  97. Updated IPN coordinates for GRB000801
  98. IPN localization of GRB000801
  99. IPN localization of GRB000801
  100. IPN localization of GRB000730B

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