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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"

31728 results found.

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

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