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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"

32531 results found.

  1. CORRECTION to XMM-Newton observation of GRB001025
  2. GRB001109: Optical observations
  3. GRB001109, R-band optical observations
  4. GRB001109, Radio observations
  5. GRB001105 BVRI field photometry correction
  6. GRB001105, BVRI field photometry
  7. GRB 001105, R-band observation
  8. GRB 991208: HST Imaging of the Host Galaxy
  9. GRB000926: R-image of the host galaxy
  10. GRB 001025B, I-band observations
  11. XMM-Newton observation of GRB001025
  12. GRB001025B, Radio observations
  13. GRB 001025 Optical Observations
  14. GRB 001025A, optical observation
  15. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  16. IPN triangulation of GRB001025
  17. GRB001007: Optical observations
  18. GRB001007, Radio observations
  19. GRB 001018, Possible Radio Afterglow
  20. CORRECTION TO PEAK FLUX OF GRB001018
  21. GRB 000926: Improved Absorber Redshift
  22. V,R,I band observations of GRB000926
  23. The Likely Optical/Infrared Afterglow of GRB 001011
  24. HETE positions added to GCN
  25. GRB 001007, BVR-band observations
  26. GRB001007: Optical observations
  27. CONCAM null result on GRB001005
  28. GRB 000926 : the host galaxy
  29. GRB 000926 Chandra Observation
  30. Public availability of BeppoSAX data of GRB000926
  31. GRB000926: X-ray afterglow by BeppoSAX: revised fluxes (fwd)
  32. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  33. GRB000926 - Optical observations
  34. GRB000926 - Optical observations
  35. GRB 000926, Optical Decay
  36. GRB000911: VLT infrared observation
  37. GRB000926 - Optical observations
  38. GRB000926 - Optical observations
  39. GRB 000926: optical observations
  40. GRB 000926, Optical Observations
  41. GRB000926 - Optical observations
  42. GRB000911: optical VLT observations
  43. GRB000926 : increasing optical decay slope
  44. GRB000926 optical observations
  45. GRB000926 - Optical observations
  46. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  47. J and K band observations of GRB 000926
  48. GRB000911 Optical Observations
  49. GRB 000926: Lightcurve Update and Predictions
  50. GRB 000926, optical observation by Oksanen (vsnet-grb)
  51. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  52. GRB000926: Optical observations
  53. GRB 000926: Preliminary R-band Lightcurve
  54. GRB 000926 HST/Chandra TOO Status
  55. Spectroscopic Redshift of GRB 000926
  56. GRB 000926, Optical Observation
  57. GRB000926, radio observations
  58. GRB 000926: Optical candidate
  59. Optical candidate for GRB000926
  60. IPN triangulation of GRB000926
  61. GRB 000911, BVRI field photometry
  62. GRB000911: Corrected coordinates
  63. GRB000911: Sub-millimeter observations
  64. GRB000911: Optical Transient
  65. GRB000911, Radio and Optical observations
  66. GRB000911, Radio observations
  67. GRB000911: Optical observations
  68. False GRB alarm from RXTE/ASM on 8 Sept 2000
  69. GRB 000830: Optical observations
  70. GRB000830: Optical observations
  71. GRB000830, TNG B-band observations
  72. GRB000830: Optical observations
  73. GRB000210, Optical observations
  74. Chandra Position of GRB000210
  75. GRB000830: Optical observations
  76. HST/STIS observations of the host galaxy of GRB 980329
  77. HST/STIS observations of the chaotic environment of GRB 980613
  78. GRB000812, TNG R-band observations
  79. GRB000801 & GRB000730, Gamma Ray Observations
  80. GRB000812, Radio observations
  81. GRB000801, VLT-Antu R-band observations
  82. GRB000301C, UBVI optical observations
  83. GRB000801, Radio Observations
  84. GRB 991208 Host Galaxy Imaging
  85. Updated IPN coordinates for GRB000801
  86. IPN localization of GRB000801
  87. IPN localization of GRB000730B
  88. GRB 990510: Possible detection of a host galaxy
  89. GRB 990510 Host Galaxy Discovery
  90. GRB 000727, optical observations
  91. GRB 990705, HST/STIS observations of the host galaxy
  92. GRB 990712: Late time HST/STIS Observations
  93. GRB 991216, HST/STIS observations
  94. GRB000620, Radio Observations
  95. GRB981226, HST/STIS observations of the host galaxy
  96. GRB000630, optical observations
  97. GRB 000630: Detection of the Optical Afterglow
  98. GRB000630, Revised BVRI Field Photometry
  99. GRB000630, Optical Observations
  100. GRB000630, optical observations

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