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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"

31729 results found.

  1. GRB 990506 R band observations
  2. GRB990510: X-ray afterglow
  3. VLT spectrum of GRB990510
  4. GRB 990510: Broad Band Break
  5. GRB 990510: BATSE Observations
  6. GRB990510: optical observation
  7. GRB 990510 Optical Observations
  8. GRB 990510, BVI photometry
  9. GRB 990510 optical observations
  10. GRB990510 optical observations
  11. GRB990510
  12. GRB 990510 optical observations
  13. GRB 990510 optical observations
  14. Galactic extinction towards GRB 990510
  15. IPN localization of GRB990510
  16. GRB 990506 Radio Observations
  17. GRB 990506: BATSE Observations
  18. GRB 990506, optical observations
  19. GRB 990506, Optical Observations
  20. GRB 990506 optical observations
  21. GRB 990506 optical observations
  22. GRB 990506, optical observations
  23. GRB990506 observation plan
  24. GRB 990506: Limits on the possible optical transient
  25. GRB 990506, armchair astronomy
  26. GRB 990506, optical observations from +1 to +3 hours
  27. GRB 990506, optical observations
  28. GRB990506 observation plan
  29. New IPN/RXTE error box for GRB990506
  30. IPN localization for GRB990506
  31. GRB 970228: Redshift and properties of the host galaxy
  32. GRB981220 VLBA observations
  33. GRB990321 REFINED IPN ANNULUS
  34. GRB990323 PRECISE IPN POSITION
  35. GRB 990316 Optical Observations
  36. GRB 990316, Radio observations
  37. GRB 990316, Optical observations
  38. GRB990316, Optical observations
  39. GRB 990316 optical observations
  40. GRB990316: simultaneous optical observation
  41. GRB990308 not a new SGR
  42. GRB 990308a and GRB 990308b
  43. GRB990308 (Trig. 7457), optical observations
  44. GRB981220, IPN localization
  45. GRB 981220, radio observations
  46. GRB 990123, Field Photometry
  47. GRB 990217, radio observations
  48. BATSE Resumes Normal Operations
  49. BATSE Flight Anomaly
  50. GRB990123: Caltech STIS Photometry and Images
  51. GRB990123 observations
  52. GRB990123, Optical Observation
  53. GRB 990123: Discovery of the Probable Host Galaxy
  54. GRB 990123: Reduced HST Images
  55. For Immediate Posting to GCN - HST Data GRB 990123 Available
  56. GRB19990123 observations
  57. GRB 990123: Updated Keck Spectroscopy Results
  58. GRB 990123 NOT Spectrum Update
  59. GRB990123, Optical observation
  60. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  61. GRB 990123: Publicly available reduced HST images
  62. GRB 990123: New Constraints on Possible Foreground Galaxies
  63. GRB990123 Optical Observations
  64. GRB990123, Probability of gravitational lensing
  65. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  66. GRB 990123: Continued Radio Observations
  67. GRB 990123: Correction to GCN 230 - C.A. Young added to author list
  68. On the Lensing Interpretation of GRB 990123
  69. Search for Potential Images of GRB 990123
  70. Search for Potential Images of GRB 990123
  71. GRB990123, Optical BVRI Observations
  72. GRB 990123: near-infrared observations.
  73. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  74. GRB990123: NIR Observation
  75. "GRB 990123: New BV Observations"
  76. GRB 990123 Optical Follow-Up
  77. GRB 990123; Addendum to GCN 223
  78. GRB 990123: BATSE Observations
  79. GRB 990123 Keck Spectrum update
  80. GRB990123 IPN annulus
  81. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  82. GRB990123 Optical Observations
  83. GRB 990123 Spectroscopic Redshifts
  84. GRB 990123: New Optical Observations, Decay Measure
  85. GRB 990123 Optical Follow-Up
  86. GRB 990123: Possible Gravitationally Lensed Burst?
  87. GRB990123, optical observation
  88. GRB 990123 optical observations
  89. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  90. GRB 990123 radio observations
  91. GRB 990123, new radio source
  92. GRB990123, Optical observation
  93. GRB 990123: Optical Decay Slope
  94. GRB 990123 r-band photometry
  95. GRB 990123 Optical Follow-up
  96. GRB990123, early optical counterpart detection
  97. GRB990123 Optical Observation
  98. GRB 990123: Bright New Source, Possible Optical Transient
  99. GRB 990123, Radio observations
  100. SN 1999E & GRB 980919

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