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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"

31730 results found.

  1. GRB990510, VI observations
  2. GRB 990506 R band observations
  3. GRB990510: X-ray afterglow
  4. VLT spectrum of GRB990510
  5. GRB 990510: Broad Band Break
  6. GRB 990510: BATSE Observations
  7. GRB990510: optical observation
  8. GRB 990510 Optical Observations
  9. GRB 990510, BVI photometry
  10. GRB 990510 optical observations
  11. GRB990510 optical observations
  12. GRB990510
  13. GRB 990510 optical observations
  14. GRB 990510 optical observations
  15. Galactic extinction towards GRB 990510
  16. IPN localization of GRB990510
  17. GRB 990506 Radio Observations
  18. GRB 990506: BATSE Observations
  19. GRB 990506, optical observations
  20. GRB 990506, Optical Observations
  21. GRB 990506 optical observations
  22. GRB 990506 optical observations
  23. GRB 990506, optical observations
  24. GRB990506 observation plan
  25. GRB 990506: Limits on the possible optical transient
  26. GRB 990506, armchair astronomy
  27. GRB 990506, optical observations from +1 to +3 hours
  28. GRB 990506, optical observations
  29. GRB990506 observation plan
  30. New IPN/RXTE error box for GRB990506
  31. IPN localization for GRB990506
  32. GRB 970228: Redshift and properties of the host galaxy
  33. GRB981220 VLBA observations
  34. GRB990321 REFINED IPN ANNULUS
  35. GRB990323 PRECISE IPN POSITION
  36. GRB 990316 Optical Observations
  37. GRB 990316, Radio observations
  38. GRB 990316, Optical observations
  39. GRB990316, Optical observations
  40. GRB 990316 optical observations
  41. GRB990316: simultaneous optical observation
  42. GRB990308 not a new SGR
  43. GRB 990308a and GRB 990308b
  44. GRB990308 (Trig. 7457), optical observations
  45. GRB981220, IPN localization
  46. GRB 981220, radio observations
  47. GRB 990123, Field Photometry
  48. GRB 990217, radio observations
  49. BATSE Resumes Normal Operations
  50. BATSE Flight Anomaly
  51. GRB990123: Caltech STIS Photometry and Images
  52. GRB990123 observations
  53. GRB990123, Optical Observation
  54. GRB 990123: Discovery of the Probable Host Galaxy
  55. GRB 990123: Reduced HST Images
  56. For Immediate Posting to GCN - HST Data GRB 990123 Available
  57. GRB19990123 observations
  58. GRB 990123: Updated Keck Spectroscopy Results
  59. GRB 990123 NOT Spectrum Update
  60. GRB990123, Optical observation
  61. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  62. GRB 990123: Publicly available reduced HST images
  63. GRB 990123: New Constraints on Possible Foreground Galaxies
  64. GRB990123 Optical Observations
  65. GRB990123, Probability of gravitational lensing
  66. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  67. GRB 990123: Continued Radio Observations
  68. GRB 990123: Correction to GCN 230 - C.A. Young added to author list
  69. On the Lensing Interpretation of GRB 990123
  70. Search for Potential Images of GRB 990123
  71. Search for Potential Images of GRB 990123
  72. GRB990123, Optical BVRI Observations
  73. GRB 990123: near-infrared observations.
  74. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  75. GRB990123: NIR Observation
  76. "GRB 990123: New BV Observations"
  77. GRB 990123 Optical Follow-Up
  78. GRB 990123; Addendum to GCN 223
  79. GRB 990123: BATSE Observations
  80. GRB 990123 Keck Spectrum update
  81. GRB990123 IPN annulus
  82. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  83. GRB990123 Optical Observations
  84. GRB 990123 Spectroscopic Redshifts
  85. GRB 990123: New Optical Observations, Decay Measure
  86. GRB 990123 Optical Follow-Up
  87. GRB 990123: Possible Gravitationally Lensed Burst?
  88. GRB990123, optical observation
  89. GRB 990123 optical observations
  90. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  91. GRB 990123 radio observations
  92. GRB 990123, new radio source
  93. GRB990123, Optical observation
  94. GRB 990123: Optical Decay Slope
  95. GRB 990123 r-band photometry
  96. GRB 990123 Optical Follow-up
  97. GRB990123, early optical counterpart detection
  98. GRB990123 Optical Observation
  99. GRB 990123: Bright New Source, Possible Optical Transient
  100. GRB 990123, Radio observations

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