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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"

36692 results found.

  1. Optical Observations of GRB 990506
  2. GRB 990506 Radio Transient
  3. GRB990527 Optical Observations
  4. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  5. IPN error box for GRB990527
  6. Late Afterglows of GRBs 990510, 990123
  7. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  8. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  9. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  10. GRB 990506 optical observation
  11. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  12. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  13. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  14. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  15. radio observations of X-ray/GRB transient field
  16. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  17. Optical report on X-ray/GRB transient
  18. radio detection of X-ray/GRB transient
  19. BeppoSAX: A new fast X-ray transient
  20. GRB 990510: optical observations
  21. GRB990510: photometric and spectroscopic observations with the VLT
  22. GRB 990510: optical linear polarization
  23. GRB 990510: optical observations
  24. GRB990510, VI observations
  25. GRB 990506 R band observations
  26. GRB990510: X-ray afterglow
  27. GRB 990510: optical observation
  28. VLT spectrum of GRB990510
  29. GRB 990510: Broad Band Break
  30. GRB 990510: BATSE Observations
  31. GRB 990510 Optical Observations
  32. GRB 990510, BVI photometry
  33. GRB 990510 optical observations
  34. GRB 990510: BeppoSAX/GRBM observations
  35. GRB990510 optical observations
  36. GRB 990510 optical observations
  37. GRB 990510 optical observations
  38. Galactic extinction towards GRB 990510
  39. GRB 990510 optical observations
  40. IPN localization of GRB990510
  41. GRB 990506 Radio Observations
  42. GRB 990123, optical monitoring
  43. GRB 990506: BATSE Observations
  44. GRB 990506, optical observations
  45. GRB 990510: Final BeppoSAX-WFC Coordinates
  46. GRB 990506, Optical Observations
  47. GRB 990506 optical observations
  48. GRB 990506 optical observations
  49. GRB 990506, optical observations
  50. GRB990506 observation plan
  51. Refined IPN error box for GRB990506
  52. GRB 990506: Limits on the possible optical transient
  53. GRB 990506, armchair astronomy
  54. GRB 990506, optical observations from +1 to +3 hours
  55. GRB 990506, optical observations
  56. GRB990506 observation plan
  57. New IPN/RXTE error box for GRB990506
  58. IPN localization for GRB990506
  59. GRB 970228: Redshift and properties of the host galaxy
  60. IPN localization of GRB990427
  61. GRB981220 VLBA observations
  62. GRB990321 REFINED IPN ANNULUS
  63. GRB990323 PRECISE IPN POSITION
  64. GRB990321 IPN TRIANGULATION
  65. GRB 990316 Optical Observations
  66. GRB 990316, Radio observations
  67. GRB 990316, Optical observations
  68. GRB990316, Optical observations
  69. GRB 990316 optical observations
  70. GRB990316: simultaneous optical observation
  71. ASM/IPN error box for GRB 990308 (BATSE #7457)
  72. GRB990308 not a new SGR
  73. GRB 990308a and GRB 990308b
  74. GRB990308 (Trig. 7457), optical observations
  75. GRB981220, IPN localization
  76. GRB 981220, radio observations
  77. GRB 990123, Field Photometry
  78. GRB 990217 Optical Observations
  79. GRB 990217, radio observations
  80. Optical Observations of GRB990217
  81. GRB990123: Caltech STIS Photometry and Images
  82. GRB990123 observations
  83. GRB990123, Optical Observation
  84. GRB 990123: Discovery of the Probable Host Galaxy
  85. GRB 990123: Reduced HST Images
  86. For Immediate Posting to GCN - HST Data GRB 990123 Available
  87. GRB19990123 observations
  88. GRB 990123: BVRI standards in the field
  89. GRB 990123: Updated Keck Spectroscopy Results
  90. GRB981220, field photometry
  91. GRB 990123 NOT Spectrum Update
  92. GRB990123, Optical observation
  93. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  94. GRB 990123: Publicly available reduced HST images
  95. GRB990123, Upcoming HST Service Observations
  96. GRB 990123: New Constraints on Possible Foreground Galaxies
  97. GRB990123 Optical Observations
  98. GRB990123, Probability of gravitational lensing
  99. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  100. GRB 990123: Continued Radio Observations

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