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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"

37202 results found.

  1. GRB001120, optical observations
  2. IPN triangulation of GRB001120
  3. Optical/NIR observations of GRB001109
  4. GRB 001109: deep JHK upper limits
  5. GRB 001109 X-ray afterglow with BeppoSAX
  6. GRB001109: Optical observations
  7. GRB001109: BeppoSAX/NFI Observations
  8. GRB001109, R-band optical observations
  9. GRB001109, Radio observations
  10. BeppoSAX ALERT: GRB001109
  11. GRB001105 BVRI field photometry correction
  12. GRB001105, BVRI field photometry
  13. GRB 001105, R-band observation
  14. IPN TRIANGULATION OF GRB001105
  15. GRB 001025B, Optical obervations
  16. GRB 991208: HST Imaging of the Host Galaxy
  17. GRB000926: R-image of the host galaxy
  18. GRB 001025B, I-band observations
  19. GRB 001025 Optical Observations
  20. GRB 001025A, optical observation
  21. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  22. IPN triangulation of GRB001025
  23. ASM Localization of GRB 001025
  24. GRB001007, Radio observations
  25. IPN TRIANGULATION OF GRB001020
  26. GRB001019, Optical Observations
  27. GRB 001018, Possible Radio Afterglow
  28. GRB001018, Gamma Ray Observations
  29. IPN TRIANGULATION OF GRB001019
  30. IPN TRIANGULATION OF GRB001018
  31. IPN TRIANGULATION OF GRB 001017
  32. GRB 000926: Improved Absorber Redshift
  33. V,R,I band observations of GRB000926
  34. The Likely Optical/Infrared Afterglow of GRB 001011
  35. HETE positions added to GCN
  36. BeppoSAX ALERT: GRB001011
  37. GRB 001007, BVR-band observations
  38. GRB000926 - Amateur Optical Observations
  39. CONCAM null result on GRB001005
  40. IPN triangulation of GRB001007
  41. GRB 000926 : the host galaxy
  42. IPN triangulation of GRB001005
  43. GRB 000926 Chandra Observation
  44. IPN triangulation of GRB 001004
  45. Public availability of BeppoSAX data of GRB000926
  46. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  47. GRB 000926, Optical Decay
  48. GRB000926 - Optical observations
  49. GRB000926 - Optical observations
  50. GRB 000926: optical observations
  51. GRB 000926, Optical Observations
  52. GRB000926 K'-band Observation
  53. GRB000926 : increasing optical decay slope
  54. GRB000926 optical observations
  55. GRB000926 - Optical observations
  56. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  57. J and K band observations of GRB 000926
  58. GRB 000926: Lightcurve Update and Predictions
  59. GRB 000926, optical observation by Oksanen (vsnet-grb)
  60. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  61. CONCAM crude optical limits before and after GRB000926
  62. GRB 000926: Preliminary R-band Lightcurve
  63. GRB 000926 HST/Chandra TOO Status
  64. Spectroscopic Redshift of GRB 000926
  65. GRB 000926, Optical Observation
  66. GRB 000926: Optical candidate
  67. Optical candidate for GRB000926
  68. IPN triangulation of GRB000926
  69. GRB 000911, BVRI field photometry
  70. GRB000911: Sub-millimeter observations
  71. IPN triangulation of GRB000925
  72. IPN triangulation of GRB000911
  73. IPN triangulation of GRB000910
  74. False GRB alarm from RXTE/ASM on 8 Sept 2000
  75. GRB 000830: Optical observations
  76. GRB000830: Optical observations
  77. GRB000830, TNG B-band observations
  78. GRB000830, BVRI field photometry
  79. GRB000830: Optical observations
  80. GRB000210, Optical observations
  81. Chandra Position of GRB000210
  82. "Snapshot" afterglow IDs and GRB 000830
  83. IPN triangulation of GRB000830
  84. HST/STIS observations of the host galaxy of GRB 980329
  85. HST/STIS observations of the chaotic environment of GRB 980613
  86. IPN localization of GRB000820
  87. GRB000801 & GRB000730, Gamma Ray Observations
  88. GRB000730, Gamma Ray Observations
  89. GRB000812, Radio observations
  90. IPN localization of GRB000812
  91. IPN localization of GRB000811
  92. GRB000801, Gamma Ray Observations
  93. GRB000801, VLT-Antu R-band observations
  94. GRB 991208 Host Galaxy Imaging
  95. Updated IPN coordinates for GRB000801
  96. IPN localization of GRB000801
  97. IPN localization of GRB000730B
  98. IPN localization of GRB000730B
  99. IPN localization of GRB000730
  100. GRB 990510: Possible detection of a host galaxy

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