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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"

32510 results found.

  1. V,R,I band observations of GRB000926
  2. The Likely Optical/Infrared Afterglow of GRB 001011
  3. HETE positions added to GCN
  4. GRB 001007, BVR-band observations
  5. GRB001007: Optical observations
  6. CONCAM null result on GRB001005
  7. GRB 000926 : the host galaxy
  8. GRB 000926 Chandra Observation
  9. Public availability of BeppoSAX data of GRB000926
  10. GRB000926: X-ray afterglow by BeppoSAX: revised fluxes (fwd)
  11. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  12. GRB000926 - Optical observations
  13. GRB000926 - Optical observations
  14. GRB 000926, Optical Decay
  15. GRB000911: VLT infrared observation
  16. GRB000926 - Optical observations
  17. GRB000926 - Optical observations
  18. GRB 000926: optical observations
  19. GRB 000926, Optical Observations
  20. GRB000926 - Optical observations
  21. GRB000911: optical VLT observations
  22. GRB000926 : increasing optical decay slope
  23. GRB000926 optical observations
  24. GRB000926 - Optical observations
  25. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  26. J and K band observations of GRB 000926
  27. GRB000911 Optical Observations
  28. GRB 000926: Lightcurve Update and Predictions
  29. GRB 000926, optical observation by Oksanen (vsnet-grb)
  30. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  31. GRB000926: Optical observations
  32. GRB 000926: Preliminary R-band Lightcurve
  33. GRB 000926 HST/Chandra TOO Status
  34. Spectroscopic Redshift of GRB 000926
  35. GRB 000926, Optical Observation
  36. GRB000926, radio observations
  37. GRB 000926: Optical candidate
  38. Optical candidate for GRB000926
  39. IPN triangulation of GRB000926
  40. GRB 000911, BVRI field photometry
  41. GRB000911: Corrected coordinates
  42. GRB000911: Sub-millimeter observations
  43. GRB000911: Optical Transient
  44. GRB000911, Radio and Optical observations
  45. GRB000911, Radio observations
  46. GRB000911: Optical observations
  47. False GRB alarm from RXTE/ASM on 8 Sept 2000
  48. GRB 000830: Optical observations
  49. GRB000830: Optical observations
  50. GRB000830, TNG B-band observations
  51. GRB000830: Optical observations
  52. GRB000210, Optical observations
  53. Chandra Position of GRB000210
  54. GRB000830: Optical observations
  55. HST/STIS observations of the host galaxy of GRB 980329
  56. HST/STIS observations of the chaotic environment of GRB 980613
  57. GRB000812, TNG R-band observations
  58. GRB000801 & GRB000730, Gamma Ray Observations
  59. GRB000812, Radio observations
  60. GRB000801, VLT-Antu R-band observations
  61. GRB000301C, UBVI optical observations
  62. GRB000801, Radio Observations
  63. GRB 991208 Host Galaxy Imaging
  64. Updated IPN coordinates for GRB000801
  65. IPN localization of GRB000801
  66. IPN localization of GRB000730B
  67. GRB 990510: Possible detection of a host galaxy
  68. GRB 990510 Host Galaxy Discovery
  69. GRB 000727, optical observations
  70. GRB 990705, HST/STIS observations of the host galaxy
  71. GRB 990712: Late time HST/STIS Observations
  72. GRB 991216, HST/STIS observations
  73. GRB000620, Radio Observations
  74. GRB981226, HST/STIS observations of the host galaxy
  75. GRB000630, optical observations
  76. GRB 000630: Detection of the Optical Afterglow
  77. GRB000630, Revised BVRI Field Photometry
  78. GRB000630, Optical Observations
  79. GRB000630, optical observations
  80. GRB000630, optical observations
  81. GRB000630, optical observations
  82. GRB000630, optical observations
  83. GRB000630: Optical observations
  84. GRB000630, Radio Observations
  85. possible optical counterpart of GRB 000630
  86. GRB 000623, optical observations
  87. GRB 000620, optical observations
  88. GRB000418, HST/STIS Observations
  89. GRB990123: Late-time HST/STIS observations of the host
  90. GRB 990506, HST/STIS Observations of the Host Galaxy
  91. GRB 000620: J-band observations
  92. GRB000620, optical observations
  93. GRB000615: H-band observations
  94. GRB990308, HST/STIS observations of the host galaxy
  95. GRB000620 - Optical observations
  96. GRB000620 Optical observations
  97. IPN annulus for GRB000620
  98. GRB000615, Radio observations
  99. GRB000607, optical observations
  100. GRB 000615: NIR further observations

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