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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"

32495 results found.

  1. GRB000926 - Optical observations
  2. GRB000926 - Optical observations
  3. GRB 000926: optical observations
  4. GRB 000926, Optical Observations
  5. GRB000926 - Optical observations
  6. GRB000911: optical VLT observations
  7. GRB000926 : increasing optical decay slope
  8. GRB000926 optical observations
  9. GRB000926 - Optical observations
  10. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  11. J and K band observations of GRB 000926
  12. GRB000911 Optical Observations
  13. GRB 000926: Lightcurve Update and Predictions
  14. GRB 000926, optical observation by Oksanen (vsnet-grb)
  15. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  16. GRB000926: Optical observations
  17. GRB 000926: Preliminary R-band Lightcurve
  18. GRB 000926 HST/Chandra TOO Status
  19. Spectroscopic Redshift of GRB 000926
  20. GRB 000926, Optical Observation
  21. GRB000926, radio observations
  22. GRB 000926: Optical candidate
  23. Optical candidate for GRB000926
  24. IPN triangulation of GRB000926
  25. GRB 000911, BVRI field photometry
  26. GRB000911: Corrected coordinates
  27. GRB000911: Sub-millimeter observations
  28. GRB000911: Optical Transient
  29. GRB000911, Radio and Optical observations
  30. GRB000911, Radio observations
  31. GRB000911: Optical observations
  32. False GRB alarm from RXTE/ASM on 8 Sept 2000
  33. GRB 000830: Optical observations
  34. GRB000830: Optical observations
  35. GRB000830, TNG B-band observations
  36. GRB000830: Optical observations
  37. GRB000210, Optical observations
  38. Chandra Position of GRB000210
  39. GRB000830: Optical observations
  40. HST/STIS observations of the host galaxy of GRB 980329
  41. HST/STIS observations of the chaotic environment of GRB 980613
  42. GRB000812, TNG R-band observations
  43. GRB000801 & GRB000730, Gamma Ray Observations
  44. GRB000812, Radio observations
  45. GRB000801, VLT-Antu R-band observations
  46. GRB000301C, UBVI optical observations
  47. GRB000801, Radio Observations
  48. GRB 991208 Host Galaxy Imaging
  49. Updated IPN coordinates for GRB000801
  50. IPN localization of GRB000801
  51. IPN localization of GRB000730B
  52. GRB 990510: Possible detection of a host galaxy
  53. GRB 990510 Host Galaxy Discovery
  54. GRB 000727, optical observations
  55. GRB 990705, HST/STIS observations of the host galaxy
  56. GRB 990712: Late time HST/STIS Observations
  57. GRB 991216, HST/STIS observations
  58. GRB000620, Radio Observations
  59. GRB981226, HST/STIS observations of the host galaxy
  60. GRB000630, optical observations
  61. GRB 000630: Detection of the Optical Afterglow
  62. GRB000630, Revised BVRI Field Photometry
  63. GRB000630, Optical Observations
  64. GRB000630, optical observations
  65. GRB000630, optical observations
  66. GRB000630, optical observations
  67. GRB000630, optical observations
  68. GRB000630: Optical observations
  69. GRB000630, Radio Observations
  70. possible optical counterpart of GRB 000630
  71. GRB 000623, optical observations
  72. GRB 000620, optical observations
  73. GRB000418, HST/STIS Observations
  74. GRB990123: Late-time HST/STIS observations of the host
  75. GRB 990506, HST/STIS Observations of the Host Galaxy
  76. GRB 000620: J-band observations
  77. GRB000620, optical observations
  78. GRB000615: H-band observations
  79. GRB990308, HST/STIS observations of the host galaxy
  80. GRB000620 - Optical observations
  81. GRB000620 Optical observations
  82. IPN annulus for GRB000620
  83. GRB000615, Radio observations
  84. GRB000607, optical observations
  85. GRB 000615: NIR further observations
  86. GRB990123, HST/STIS observations of the host galaxy
  87. GRB000616 optical observations
  88. GRB 000615, near-infrared observations
  89. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  90. GRB000615, further R-band photometry
  91. GRB 000615: NIR observations
  92. GRB000615, R-band photometry
  93. GRB980425, HST/STIS observations of the host galaxy
  94. The Hosts of GRB 980703 and GRB 971214
  95. GRB 000301C: Further Late-Time HST/STIS observations
  96. GRB000528: follow-up X-ray measurements and update of IPN annulus
  97. Optical Follow-up of GRB000529 Error Box
  98. GRB000607, Radio Observations
  99. GRB000604 optical non-detection
  100. GRB000604 - Optical observations

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