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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"

25760 results found.

  1. GRB001120, optical observations
  2. WSRT 4.8 GHz observations of GRB001109
  3. IPN triangulation of GRB001120
  4. GRB 001109: deep JHK upper limits
  5. GRB 001109 X-ray afterglow with BeppoSAX
  6. CORRECTION to XMM-Newton observation of GRB001025
  7. GRB001109, Radio observations
  8. GRB001105 BVRI field photometry correction
  9. GRB001105, BVRI field photometry
  10. IPN TRIANGULATION OF GRB001105
  11. GRB 001025B, Optical obervations
  12. GRB 991208: HST Imaging of the Host Galaxy
  13. GRB 001025B, I-band observations
  14. XMM-Newton observation of GRB001025
  15. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  16. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  17. GRB001007: Optical observations
  18. ASM Localization of GRB 001025
  19. GRB001007, Radio observations
  20. GRB 001018, Possible Radio Afterglow
  21. GRB001018, Gamma Ray Observations
  22. IPN TRIANGULATION OF GRB001019
  23. IPN TRIANGULATION OF GRB001018
  24. IPN TRIANGULATION OF GRB 001017
  25. V,R,I band observations of GRB000926
  26. HETE positions added to GCN
  27. GRB000926 - Amateur Optical Observations
  28. CONCAM null result on GRB001005
  29. IPN triangulation of GRB001005
  30. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  31. GRB000926 - Optical observations
  32. GRB000926 - Optical observations
  33. GRB 000926, Optical Decay
  34. GRB000911: VLT infrared observation
  35. GRB 000926, Optical Observations
  36. GRB000926 K'-band Observation
  37. J and K band observations of GRB 000926
  38. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  39. CONCAM crude optical limits before and after GRB000926
  40. GRB 000926: Preliminary R-band Lightcurve
  41. Spectroscopic Redshift of GRB 000926
  42. GRB 000926: Optical candidate
  43. Optical candidate for GRB000926
  44. GRB 000911, BVRI field photometry
  45. GRB000911, Radio and Optical observations
  46. GRB000911: Optical observations
  47. GRB000830, BVRI field photometry
  48. GRB000210, Optical observations
  49. "Snapshot" afterglow IDs and GRB 000830
  50. GRB000730, Gamma Ray Observations
  51. GRB000812, Radio observations
  52. GRB000801, Gamma Ray Observations
  53. GRB000801, VLT-Antu R-band observations
  54. GRB 991208 Host Galaxy Imaging
  55. IPN localization of GRB000730B
  56. GRB 990510: Possible detection of a host galaxy
  57. GRB 990510 Host Galaxy Discovery
  58. IPN localization of GRB000727
  59. GRB 990712: Late time HST/STIS Observations
  60. GRB 991216, HST/STIS observations
  61. GRB000620, Radio Observations
  62. GRB000630, optical observations
  63. GRB000630, Revised BVRI Field Photometry
  64. GRB000630, Optical Observations
  65. GRB000630, optical observations
  66. GRB000630, optical observations
  67. GRB000630, BVRI Field Photometry
  68. GRB000630, optical observations
  69. GRB000630: Optical observations
  70. GRB000630, Radio Observations
  71. possible optical counterpart of GRB 000630
  72. GRB 000620, optical observations
  73. GRB000418, HST/STIS Observations
  74. GRB990123: Late-time HST/STIS observations of the host
  75. GRB000620, optical observations
  76. GRB000615: H-band observations
  77. GRB990308, HST/STIS observations of the host galaxy
  78. GRB000620 - Optical observations
  79. GRB000620 Optical observations
  80. GRB000620: BeppoSAX WFC and GRBM detection
  81. GRB000607, optical observations
  82. GRB 000615: NIR further observations
  83. GRB990123, HST/STIS observations of the host galaxy
  84. GRB000616 optical observations
  85. GRB 000615, near-infrared observations
  86. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  87. GRB000615, further R-band photometry
  88. GRB 000615: NIR observations
  89. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  90. GRB000615, R-band photometry
  91. The Hosts of GRB 980703 and GRB 971214
  92. GRB 000301C: Further Late-Time HST/STIS observations
  93. GRB000528: follow-up X-ray measurements and update of IPN annulus
  94. GRB980519, HST/STIS observations of the host galaxy
  95. GRB000604 optical non-detection
  96. GRB000604 - Optical observations
  97. GRB000604, optical observations
  98. GRB000528, optical observations at ESO
  99. GRB 000604 optical observations
  100. GRB 000418: Detection of the Host Galaxy

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