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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"

42581 results found.

  1. HETE-2 Launches Successfully
  2. IPN triangulation of GRB001005
  3. HETE-2 48 hour Launch Delay
  4. GRB 000926 Chandra Observation
  5. IPN triangulation of GRB 001004
  6. Public availability of BeppoSAX data of GRB000926
  7. GRB000926: X-ray afterglow by BeppoSAX: revised fluxes (fwd)
  8. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  9. GRB000926 - Optical observations
  10. GRB000926 - Optical observations
  11. GRB 000926, Optical Decay
  12. GRB000911: VLT infrared observation
  13. GRB000926 - Optical observations
  14. GRB000926 - Optical observations
  15. GRB 000926: optical observations
  16. GRB000926 - Optical observations
  17. GRB000911: optical VLT observations
  18. GRB000926 K'-band Observation
  19. GRB000926 : increasing optical decay slope
  20. GRB000926 optical observations
  21. GRB000926 - Optical observations
  22. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  23. J and K band observations of GRB 000926
  24. GRB000911 Optical Observations
  25. GRB 000926: Lightcurve Update and Predictions
  26. GRB 000926, optical observation by Oksanen (vsnet-grb)
  27. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  28. GRB000926: Optical observations
  29. CONCAM crude optical limits before and after GRB000926
  30. GRB 000926: Preliminary R-band Lightcurve
  31. GRB 000926 HST/Chandra TOO Status
  32. Spectroscopic Redshift of GRB 000926
  33. GRB 000926, Optical Observation
  34. GRB000926, radio observations
  35. GRB 000926: Optical candidate
  36. Optical candidate for GRB000926
  37. IPN triangulation of GRB000926
  38. IPN triangulation of GRB000926
  39. GRB 000911, BVRI field photometry
  40. GRB000911: Corrected coordinates
  41. GRB000911: Sub-millimeter observations
  42. IPN triangulation of GRB000925
  43. GRB000911: Optical Transient
  44. GRB000911, Radio and Optical observations
  45. GRB000911, Radio observations
  46. IPN triangulation of GRB000911
  47. IPN triangulation of GRB000910
  48. False GRB alarm from RXTE/ASM on 8 Sept 2000
  49. GRB 000830: Optical observations
  50. GRB000830: Optical observations
  51. GRB000830, TNG B-band observations
  52. GRB000830, BVRI field photometry
  53. GRB000830: Optical observations
  54. GRB000210, Optical observations
  55. "Snapshot" afterglow IDs and GRB 000830
  56. GRB000830: Optical observations
  57. IPN triangulation of GRB000830
  58. HST/STIS observations of the host galaxy of GRB 980329
  59. HST/STIS observations of the chaotic environment of GRB 980613
  60. IPN localization of GRB000820
  61. SGR 1806-20 burst activity
  62. GRB000812, TNG R-band observations
  63. GRB000730, Gamma Ray Observations
  64. GRB000812, Radio observations
  65. IPN localization of GRB000812
  66. IPN localization of GRB000811
  67. GRB000801, Gamma Ray Observations
  68. GRB000801, VLT-Antu R-band observations
  69. GRB000301C, UBVI optical observations
  70. GRB000801, Radio Observations
  71. GRB 991208 Host Galaxy Imaging
  72. IPN localization of GRB000801
  73. IPN localization of GRB000730B
  74. IPN localization of GRB000730B
  75. IPN localization of GRB000730
  76. GRB 990510: Possible detection of a host galaxy
  77. GRB 990510 Host Galaxy Discovery
  78. GRB 000727, optical observations
  79. IPN localization of GRB000727
  80. GRB 990705, HST/STIS observations of the host galaxy
  81. GRB 990712: Late time HST/STIS Observations
  82. GRB 991216, HST/STIS observations
  83. GRB000620, Radio Observations
  84. GRB981226, HST/STIS observations of the host galaxy
  85. GRB000630, optical observations
  86. GRB 000630: Detection of the Optical Afterglow
  87. GRB000630, Revised BVRI Field Photometry
  88. GRB000630, Optical Observations
  89. GRB000630, optical observations
  90. GRB000630, optical observations
  91. GRB000630, BVRI Field Photometry
  92. GRB000630, optical observations
  93. GRB000630, optical observations
  94. GRB000630: Optical observations
  95. GRB000630, Radio Observations
  96. possible optical counterpart of GRB 000630
  97. IPN triangulation of GRB000630
  98. GRB 000623, optical observations
  99. GRB 000620, optical observations
  100. GRB000418, HST/STIS Observations

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