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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"

32508 results found.

  1. HETE positions added to GCN
  2. GRB 001007, BVR-band observations
  3. GRB001007: Optical observations
  4. CONCAM null result on GRB001005
  5. GRB 000926 : the host galaxy
  6. GRB 000926 Chandra Observation
  7. Public availability of BeppoSAX data of GRB000926
  8. GRB000926: X-ray afterglow by BeppoSAX: revised fluxes (fwd)
  9. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  10. GRB000926 - Optical observations
  11. GRB000926 - Optical observations
  12. GRB 000926, Optical Decay
  13. GRB000911: VLT infrared observation
  14. GRB000926 - Optical observations
  15. GRB000926 - Optical observations
  16. GRB 000926: optical observations
  17. GRB 000926, Optical Observations
  18. GRB000926 - Optical observations
  19. GRB000911: optical VLT observations
  20. GRB000926 : increasing optical decay slope
  21. GRB000926 optical observations
  22. GRB000926 - Optical observations
  23. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  24. J and K band observations of GRB 000926
  25. GRB000911 Optical Observations
  26. GRB 000926: Lightcurve Update and Predictions
  27. GRB 000926, optical observation by Oksanen (vsnet-grb)
  28. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  29. GRB000926: Optical observations
  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. GRB 000911, BVRI field photometry
  39. GRB000911: Corrected coordinates
  40. GRB000911: Sub-millimeter observations
  41. GRB000911: Optical Transient
  42. GRB000911, Radio and Optical observations
  43. GRB000911, Radio observations
  44. GRB000911: Optical observations
  45. False GRB alarm from RXTE/ASM on 8 Sept 2000
  46. GRB 000830: Optical observations
  47. GRB000830: Optical observations
  48. GRB000830, TNG B-band observations
  49. GRB000830: Optical observations
  50. GRB000210, Optical observations
  51. Chandra Position of GRB000210
  52. GRB000830: Optical observations
  53. HST/STIS observations of the host galaxy of GRB 980329
  54. HST/STIS observations of the chaotic environment of GRB 980613
  55. GRB000812, TNG R-band observations
  56. GRB000801 & GRB000730, Gamma Ray Observations
  57. GRB000812, Radio observations
  58. GRB000801, VLT-Antu R-band observations
  59. GRB000301C, UBVI optical observations
  60. GRB000801, Radio Observations
  61. GRB 991208 Host Galaxy Imaging
  62. Updated IPN coordinates for GRB000801
  63. IPN localization of GRB000801
  64. IPN localization of GRB000730B
  65. GRB 990510: Possible detection of a host galaxy
  66. GRB 990510 Host Galaxy Discovery
  67. GRB 000727, optical observations
  68. GRB 990705, HST/STIS observations of the host galaxy
  69. GRB 990712: Late time HST/STIS Observations
  70. GRB 991216, HST/STIS observations
  71. GRB000620, Radio Observations
  72. GRB981226, HST/STIS observations of the host galaxy
  73. GRB000630, optical observations
  74. GRB 000630: Detection of the Optical Afterglow
  75. GRB000630, Revised BVRI Field Photometry
  76. GRB000630, Optical Observations
  77. GRB000630, optical observations
  78. GRB000630, optical observations
  79. GRB000630, optical observations
  80. GRB000630, optical observations
  81. GRB000630: Optical observations
  82. GRB000630, Radio Observations
  83. possible optical counterpart of GRB 000630
  84. GRB 000623, optical observations
  85. GRB 000620, optical observations
  86. GRB000418, HST/STIS Observations
  87. GRB990123: Late-time HST/STIS observations of the host
  88. GRB 990506, HST/STIS Observations of the Host Galaxy
  89. GRB 000620: J-band observations
  90. GRB000620, optical observations
  91. GRB000615: H-band observations
  92. GRB990308, HST/STIS observations of the host galaxy
  93. GRB000620 - Optical observations
  94. GRB000620 Optical observations
  95. IPN annulus for GRB000620
  96. GRB000615, Radio observations
  97. GRB000607, optical observations
  98. GRB 000615: NIR further observations
  99. GRB990123, HST/STIS observations of the host galaxy
  100. GRB000616 optical observations

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