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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"

40748 results found.

  1. HETE-2 Launches Successfully
  2. GRB 000926 Chandra Observation
  3. Public availability of BeppoSAX data of GRB000926
  4. GRB000926: X-ray afterglow by BeppoSAX: revised fluxes (fwd)
  5. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  6. GRB000926 - Optical observations
  7. GRB000926 - Optical observations
  8. GRB 000926, Optical Decay
  9. GRB000911: VLT infrared observation
  10. GRB000926 - Optical observations
  11. GRB000926 - Optical observations
  12. GRB 000926: optical observations
  13. GRB 000926, Optical Observations
  14. GRB000926 - Optical observations
  15. GRB000911: optical VLT observations
  16. GRB000926 K'-band Observation
  17. GRB000926 : increasing optical decay slope
  18. GRB000926 optical observations
  19. GRB000926 - Optical observations
  20. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  21. J and K band observations of GRB 000926
  22. GRB000911 Optical Observations
  23. GRB 000926: Lightcurve Update and Predictions
  24. GRB 000926, optical observation by Oksanen (vsnet-grb)
  25. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  26. GRB000926: Optical observations
  27. CONCAM crude optical limits before and after GRB000926
  28. GRB 000926: Preliminary R-band Lightcurve
  29. GRB 000926 HST/Chandra TOO Status
  30. Spectroscopic Redshift of GRB 000926
  31. GRB 000926, Optical Observation
  32. GRB000926, radio observations
  33. GRB 000926: Optical candidate
  34. Optical candidate for GRB000926
  35. IPN triangulation of GRB000926
  36. GRB 000911, BVRI field photometry
  37. GRB000911: Corrected coordinates
  38. GRB000911: Sub-millimeter observations
  39. GRB000911: Optical Transient
  40. GRB000911, Radio and Optical observations
  41. GRB000911, Radio observations
  42. GRB000911: Optical observations
  43. False GRB alarm from RXTE/ASM on 8 Sept 2000
  44. GRB 000830: Optical observations
  45. GRB000830: Optical observations
  46. GRB000830, TNG B-band observations
  47. GRB000830, BVRI field photometry
  48. GRB000830: Optical observations
  49. GRB000210, Optical observations
  50. Chandra Position of GRB000210
  51. "Snapshot" afterglow IDs and GRB 000830
  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. GRB000730, Gamma Ray Observations
  58. GRB000812, Radio observations
  59. GRB000801, Gamma Ray 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 GRB000801
  67. IPN localization of GRB000730B
  68. IPN localization of GRB000730B
  69. GRB 990510: Possible detection of a host galaxy
  70. GRB 990510 Host Galaxy Discovery
  71. GRB 000727, optical observations
  72. IPN localization of GRB000727
  73. GRB 990705, HST/STIS observations of the host galaxy
  74. GRB 990712: Late time HST/STIS Observations
  75. GRB 991216, HST/STIS observations
  76. GRB000620, Radio Observations
  77. GRB981226, HST/STIS observations of the host galaxy
  78. GRB000630, optical observations
  79. GRB 000630: Detection of the Optical Afterglow
  80. GRB000630, Revised BVRI Field Photometry
  81. GRB000630, Optical Observations
  82. GRB000630, optical observations
  83. GRB000630, optical observations
  84. GRB000630, BVRI Field Photometry
  85. GRB000630, optical observations
  86. GRB000630, optical observations
  87. GRB000630: Optical observations
  88. GRB000630, Radio Observations
  89. possible optical counterpart of GRB 000630
  90. GRB 000623, optical observations
  91. GRB 000620, optical observations
  92. GRB000418, HST/STIS Observations
  93. GRB990123: Late-time HST/STIS observations of the host
  94. GRB 990506, HST/STIS Observations of the Host Galaxy
  95. GRB 000620: J-band observations
  96. GRB000620, optical observations
  97. GRB000615: H-band observations
  98. GRB990308, HST/STIS observations of the host galaxy
  99. GRB000620 - Optical observations
  100. GRB000620 Optical observations

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