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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"

45645 results found.

  1. GRB001007: Optical observations
  2. CONCAM null result on GRB001005
  3. IPN triangulation of GRB001007
  4. GRB 000926 : the host galaxy
  5. HETE-2 Launches Successfully
  6. IPN triangulation of GRB001005
  7. HETE-2 48 hour Launch Delay
  8. GRB 000926 Chandra Observation
  9. IPN triangulation of GRB 001004
  10. Public availability of BeppoSAX data of GRB000926
  11. GRB000926: X-ray afterglow by BeppoSAX: revised fluxes (fwd)
  12. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  13. GRB000926 - Optical observations
  14. GRB000926 - Optical observations
  15. GRB 000926, Optical Decay
  16. GRB000911: VLT infrared observation
  17. GRB000926 - Optical observations
  18. GRB000926 - Optical observations
  19. GRB 000926: optical observations
  20. GRB 000926, Optical Observations
  21. GRB000926 - Optical observations
  22. GRB000911: optical VLT observations
  23. GRB000926 K'-band Observation
  24. GRB000926 : increasing optical decay slope
  25. GRB000926 optical observations
  26. GRB000926 - Optical observations
  27. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  28. J and K band observations of GRB 000926
  29. GRB000911 Optical Observations
  30. GRB 000926: Lightcurve Update and Predictions
  31. GRB 000926, optical observation by Oksanen (vsnet-grb)
  32. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  33. GRB000926: Optical observations
  34. CONCAM crude optical limits before and after GRB000926
  35. GRB 000926: Preliminary R-band Lightcurve
  36. GRB 000926 HST/Chandra TOO Status
  37. Spectroscopic Redshift of GRB 000926
  38. GRB 000926, Optical Observation
  39. GRB000926, radio observations
  40. GRB 000926: Optical candidate
  41. Optical candidate for GRB000926
  42. IPN triangulation of GRB000926
  43. IPN triangulation of GRB000926
  44. GRB 000911, BVRI field photometry
  45. GRB000911: Corrected coordinates
  46. GRB000911: Sub-millimeter observations
  47. IPN triangulation of GRB000925
  48. GRB000911: Optical Transient
  49. GRB000911, Radio and Optical observations
  50. GRB000911, Radio observations
  51. GRB000911: Optical observations
  52. IPN triangulation of GRB000911
  53. IPN triangulation of GRB000910
  54. False GRB alarm from RXTE/ASM on 8 Sept 2000
  55. GRB 000830: Optical observations
  56. GRB000830: Optical observations
  57. GRB000830, TNG B-band observations
  58. GRB000830, BVRI field photometry
  59. GRB000830: Optical observations
  60. GRB000210, Optical observations
  61. Chandra Position of GRB000210
  62. "Snapshot" afterglow IDs and GRB 000830
  63. GRB000830: Optical observations
  64. IPN triangulation of GRB000830
  65. HST/STIS observations of the host galaxy of GRB 980329
  66. HST/STIS observations of the chaotic environment of GRB 980613
  67. IPN localization of GRB000820
  68. SGR 1806-20 burst activity
  69. GRB000812, TNG R-band observations
  70. GRB000801 & GRB000730, Gamma Ray Observations
  71. GRB000730, Gamma Ray Observations
  72. GRB000812, Radio observations
  73. IPN localization of GRB000812
  74. IPN localization of GRB000811
  75. GRB000801, Gamma Ray Observations
  76. GRB000801, VLT-Antu R-band observations
  77. GRB000301C, UBVI optical observations
  78. GRB000801, Radio Observations
  79. GRB 991208 Host Galaxy Imaging
  80. Updated IPN coordinates for GRB000801
  81. IPN localization of GRB000801
  82. IPN localization of GRB000801
  83. IPN localization of GRB000730B
  84. IPN localization of GRB000730B
  85. IPN localization of GRB000730
  86. GRB 990510: Possible detection of a host galaxy
  87. GRB 990510 Host Galaxy Discovery
  88. GRB 000727, optical observations
  89. IPN localization of GRB000727
  90. GRB 990705, HST/STIS observations of the host galaxy
  91. GRB 990712: Late time HST/STIS Observations
  92. GRB 991216, HST/STIS observations
  93. GRB000620, Radio Observations
  94. GRB981226, HST/STIS observations of the host galaxy
  95. GRB000630, optical observations
  96. GRB 000630: Detection of the Optical Afterglow
  97. GRB000630, Revised BVRI Field Photometry
  98. GRB000630, Optical Observations
  99. GRB000630, optical observations
  100. GRB000630, optical observations

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