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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"

31733 results found.

  1. GRB 001109: deep JHK upper limits
  2. GRB 001109 X-ray afterglow with BeppoSAX
  3. CORRECTION to XMM-Newton observation of GRB001025
  4. GRB001109: Optical observations
  5. GRB001109, R-band optical observations
  6. GRB001109, Radio observations
  7. GRB001105 BVRI field photometry correction
  8. GRB001105, BVRI field photometry
  9. GRB 001105, R-band observation
  10. GRB 991208: HST Imaging of the Host Galaxy
  11. GRB000926: R-image of the host galaxy
  12. GRB 001025B, I-band observations
  13. XMM-Newton observation of GRB001025
  14. GRB001025B, Radio observations
  15. GRB 001025 Optical Observations
  16. GRB 001025A, optical observation
  17. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  18. IPN triangulation of GRB001025
  19. GRB001007: Optical observations
  20. GRB001007, Radio observations
  21. GRB 001018, Possible Radio Afterglow
  22. CORRECTION TO PEAK FLUX OF GRB001018
  23. GRB 000926: Improved Absorber Redshift
  24. V,R,I band observations of GRB000926
  25. The Likely Optical/Infrared Afterglow of GRB 001011
  26. HETE positions added to GCN
  27. GRB 001007, BVR-band observations
  28. GRB001007: Optical observations
  29. CONCAM null result on GRB001005
  30. GRB 000926 : the host galaxy
  31. GRB 000926 Chandra Observation
  32. Public availability of BeppoSAX data of GRB000926
  33. GRB000926: X-ray afterglow by BeppoSAX: revised fluxes (fwd)
  34. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  35. GRB000926 - Optical observations
  36. GRB000926 - Optical observations
  37. GRB 000926, Optical Decay
  38. GRB000911: VLT infrared observation
  39. GRB000926 - Optical observations
  40. GRB000926 - Optical observations
  41. GRB 000926: optical observations
  42. GRB 000926, Optical Observations
  43. GRB000926 - Optical observations
  44. GRB000911: optical VLT observations
  45. GRB000926 : increasing optical decay slope
  46. GRB000926 optical observations
  47. GRB000926 - Optical observations
  48. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  49. J and K band observations of GRB 000926
  50. GRB000911 Optical Observations
  51. GRB 000926: Lightcurve Update and Predictions
  52. GRB 000926, optical observation by Oksanen (vsnet-grb)
  53. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  54. GRB000926: Optical observations
  55. GRB 000926: Preliminary R-band Lightcurve
  56. GRB 000926 HST/Chandra TOO Status
  57. Spectroscopic Redshift of GRB 000926
  58. GRB 000926, Optical Observation
  59. GRB000926, radio observations
  60. GRB 000926: Optical candidate
  61. Optical candidate for GRB000926
  62. IPN triangulation of GRB000926
  63. GRB 000911, BVRI field photometry
  64. GRB000911: Corrected coordinates
  65. GRB000911: Sub-millimeter observations
  66. GRB000911: Optical Transient
  67. GRB000911, Radio and Optical observations
  68. GRB000911, Radio observations
  69. GRB000911: Optical observations
  70. False GRB alarm from RXTE/ASM on 8 Sept 2000
  71. GRB 000830: Optical observations
  72. GRB000830: Optical observations
  73. GRB000830, TNG B-band observations
  74. GRB000830: Optical observations
  75. GRB000210, Optical observations
  76. Chandra Position of GRB000210
  77. GRB000830: Optical observations
  78. HST/STIS observations of the host galaxy of GRB 980329
  79. HST/STIS observations of the chaotic environment of GRB 980613
  80. GRB000812, TNG R-band observations
  81. GRB000801 & GRB000730, Gamma Ray Observations
  82. GRB000812, Radio observations
  83. GRB000801, VLT-Antu R-band observations
  84. GRB000301C, UBVI optical observations
  85. GRB000801, Radio Observations
  86. GRB 991208 Host Galaxy Imaging
  87. Updated IPN coordinates for GRB000801
  88. IPN localization of GRB000801
  89. IPN localization of GRB000730B
  90. GRB 990510: Possible detection of a host galaxy
  91. GRB 990510 Host Galaxy Discovery
  92. GRB 000727, optical observations
  93. GRB 990705, HST/STIS observations of the host galaxy
  94. GRB 990712: Late time HST/STIS Observations
  95. GRB 991216, HST/STIS observations
  96. GRB000620, Radio Observations
  97. GRB981226, HST/STIS observations of the host galaxy
  98. GRB000630, optical observations
  99. GRB 000630: Detection of the Optical Afterglow
  100. GRB000630, Revised BVRI Field Photometry

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