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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"

33688 results found.

  1. GRB 001025 Optical Observations
  2. GRB 001025A, optical observation
  3. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  4. IPN triangulation of GRB001025
  5. ASM Localization of GRB 001025
  6. GRB001007, Radio observations
  7. IPN TRIANGULATION OF GRB001020
  8. GRB001019, Optical Observations
  9. GRB 001018, Possible Radio Afterglow
  10. GRB001018, Gamma Ray Observations
  11. IPN TRIANGULATION OF GRB001019
  12. IPN TRIANGULATION OF GRB001018
  13. IPN TRIANGULATION OF GRB 001017
  14. GRB 000926: Improved Absorber Redshift
  15. V,R,I band observations of GRB000926
  16. The Likely Optical/Infrared Afterglow of GRB 001011
  17. HETE positions added to GCN
  18. BeppoSAX ALERT: GRB001011
  19. GRB 001007, BVR-band observations
  20. GRB000926 - Amateur Optical Observations
  21. CONCAM null result on GRB001005
  22. IPN triangulation of GRB001007
  23. GRB 000926 : the host galaxy
  24. IPN triangulation of GRB001005
  25. GRB 000926 Chandra Observation
  26. IPN triangulation of GRB 001004
  27. Public availability of BeppoSAX data of GRB000926
  28. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  29. GRB 000926, Optical Decay
  30. GRB000911: VLT infrared observation
  31. GRB000926 - Optical observations
  32. GRB000926 - Optical observations
  33. GRB 000926: optical observations
  34. GRB 000926, Optical Observations
  35. GRB000911: optical VLT observations
  36. GRB000926 K'-band Observation
  37. GRB000926 : increasing optical decay slope
  38. GRB000926 optical observations
  39. GRB000926 - Optical observations
  40. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  41. J and K band observations of GRB 000926
  42. GRB 000926: Lightcurve Update and Predictions
  43. GRB 000926, optical observation by Oksanen (vsnet-grb)
  44. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  45. CONCAM crude optical limits before and after GRB000926
  46. GRB 000926: Preliminary R-band Lightcurve
  47. GRB 000926 HST/Chandra TOO Status
  48. Spectroscopic Redshift of GRB 000926
  49. GRB 000926, Optical Observation
  50. GRB 000926: Optical candidate
  51. Optical candidate for GRB000926
  52. IPN triangulation of GRB000926
  53. GRB 000911, BVRI field photometry
  54. GRB000911: Sub-millimeter observations
  55. IPN triangulation of GRB000925
  56. IPN triangulation of GRB000911
  57. IPN triangulation of GRB000910
  58. False GRB alarm from RXTE/ASM on 8 Sept 2000
  59. GRB 000830: Optical observations
  60. GRB000830: Optical observations
  61. GRB000830, TNG B-band observations
  62. GRB000830, BVRI field photometry
  63. GRB000830: Optical observations
  64. GRB000210, Optical observations
  65. Chandra Position of GRB000210
  66. "Snapshot" afterglow IDs and GRB 000830
  67. IPN triangulation of GRB000830
  68. HST/STIS observations of the host galaxy of GRB 980329
  69. HST/STIS observations of the chaotic environment of GRB 980613
  70. IPN localization of GRB000820
  71. GRB000801 & GRB000730, Gamma Ray Observations
  72. GRB000730, Gamma Ray Observations
  73. GRB000812, Radio observations
  74. IPN localization of GRB000812
  75. IPN localization of GRB000811
  76. GRB000801, Gamma Ray Observations
  77. GRB000801, VLT-Antu R-band observations
  78. GRB 991208 Host Galaxy Imaging
  79. Updated IPN coordinates for GRB000801
  80. IPN localization of GRB000801
  81. IPN localization of GRB000730B
  82. IPN localization of GRB000730B
  83. IPN localization of GRB000730
  84. GRB 990510: Possible detection of a host galaxy
  85. GRB 990510 Host Galaxy Discovery
  86. GRB 000727, optical observations
  87. IPN localization of GRB000727
  88. GRB 990705, HST/STIS observations of the host galaxy
  89. GRB 990712: Late time HST/STIS Observations
  90. GRB 991216, HST/STIS observations
  91. GRB981226, HST/STIS observations of the host galaxy
  92. GRB 000630: Detection of the Optical Afterglow
  93. GRB000630, Revised BVRI Field Photometry
  94. GRB000630, Optical Observations
  95. GRB000630, optical observations
  96. GRB000630, BVRI Field Photometry
  97. GRB000630, optical observations
  98. GRB000630: Optical observations
  99. possible optical counterpart of GRB 000630
  100. IPN triangulation of GRB000630

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