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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"

45438 results found.

  1. The Likely Optical/Infrared Afterglow of GRB 001011
  2. HETE positions added to GCN
  3. GRB001011 BeppoSAX/WFC refined position
  4. BeppoSAX ALERT: GRB001011
  5. GRB 001007, BVR-band observations
  6. GRB000926 - Amateur Optical Observations
  7. GRB001007: Optical observations
  8. CONCAM null result on GRB001005
  9. IPN triangulation of GRB001007
  10. GRB 000926 : the host galaxy
  11. HETE-2 Launches Successfully
  12. IPN triangulation of GRB001005
  13. HETE-2 48 hour Launch Delay
  14. GRB 000926 Chandra Observation
  15. IPN triangulation of GRB 001004
  16. Public availability of BeppoSAX data of GRB000926
  17. GRB000926: X-ray afterglow by BeppoSAX: revised fluxes (fwd)
  18. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  19. GRB000926 - Optical observations
  20. GRB000926 - Optical observations
  21. GRB 000926, Optical Decay
  22. GRB000911: VLT infrared observation
  23. GRB000926 - Optical observations
  24. GRB000926 - Optical observations
  25. GRB 000926: optical observations
  26. GRB 000926, Optical Observations
  27. GRB000926 - Optical observations
  28. GRB000911: optical VLT observations
  29. GRB000926 K'-band Observation
  30. GRB000926 : increasing optical decay slope
  31. GRB000926 optical observations
  32. GRB000926 - Optical observations
  33. J and K band observations of GRB 000926
  34. GRB000911 Optical Observations
  35. GRB 000926: Lightcurve Update and Predictions
  36. GRB 000926, optical observation by Oksanen (vsnet-grb)
  37. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  38. GRB000926: Optical observations
  39. CONCAM crude optical limits before and after GRB000926
  40. GRB 000926: Preliminary R-band Lightcurve
  41. GRB 000926 HST/Chandra TOO Status
  42. Spectroscopic Redshift of GRB 000926
  43. GRB 000926, Optical Observation
  44. GRB000926, radio observations
  45. GRB 000926: Optical candidate
  46. Optical candidate for GRB000926
  47. IPN triangulation of GRB000926
  48. IPN triangulation of GRB000926
  49. GRB 000911, BVRI field photometry
  50. GRB000911: Corrected coordinates
  51. GRB000911: Sub-millimeter observations
  52. IPN triangulation of GRB000925
  53. GRB000911: Optical Transient
  54. GRB000911, Radio and Optical observations
  55. GRB000911, Radio observations
  56. GRB000911: Optical observations
  57. IPN triangulation of GRB000911
  58. IPN triangulation of GRB000910
  59. False GRB alarm from RXTE/ASM on 8 Sept 2000
  60. GRB 000830: Optical observations
  61. GRB000830: Optical observations
  62. GRB000830, TNG B-band observations
  63. GRB000830, BVRI field photometry
  64. GRB000830: Optical observations
  65. GRB000210, Optical observations
  66. Chandra Position of GRB000210
  67. "Snapshot" afterglow IDs and GRB 000830
  68. GRB000830: Optical observations
  69. IPN triangulation of GRB000830
  70. HST/STIS observations of the host galaxy of GRB 980329
  71. HST/STIS observations of the chaotic environment of GRB 980613
  72. IPN localization of GRB000820
  73. SGR 1806-20 burst activity
  74. GRB000812, TNG R-band observations
  75. GRB000801 & GRB000730, Gamma Ray Observations
  76. GRB000730, Gamma Ray Observations
  77. GRB000812, Radio observations
  78. IPN localization of GRB000812
  79. IPN localization of GRB000811
  80. GRB000801, Gamma Ray Observations
  81. GRB000801, VLT-Antu R-band observations
  82. GRB000301C, UBVI optical observations
  83. GRB000801, Radio Observations
  84. GRB 991208 Host Galaxy Imaging
  85. Updated IPN coordinates for GRB000801
  86. IPN localization of GRB000801
  87. IPN localization of GRB000801
  88. IPN localization of GRB000730B
  89. IPN localization of GRB000730B
  90. IPN localization of GRB000730
  91. GRB 990510: Possible detection of a host galaxy
  92. GRB 990510 Host Galaxy Discovery
  93. GRB 000727, optical observations
  94. IPN localization of GRB000727
  95. GRB 990705, HST/STIS observations of the host galaxy
  96. GRB 990712: Late time HST/STIS Observations
  97. GRB 991216, HST/STIS observations
  98. GRB000620, Radio Observations
  99. GRB981226, HST/STIS observations of the host galaxy
  100. GRB000630, optical observations

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Download all Circulars as a .tar.gz archive (updated once a day):
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