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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"

32130 results found.

  1. GRB990323 PRECISE IPN POSITION
  2. GRB990321 IPN TRIANGULATION
  3. GRB 990316 Optical Observations
  4. GRB 990316, Radio observations
  5. GRB 990316, Optical observations
  6. GRB990316, Optical observations
  7. GRB 990316 optical observations
  8. GRB990316: simultaneous optical observation
  9. ASM/IPN error box for GRB 990308 (BATSE #7457)
  10. GRB990308 not a new SGR
  11. GRB 990308a and GRB 990308b
  12. GRB990308 (Trig. 7457), optical observations
  13. GRB981220, IPN localization
  14. GRB 981220, radio observations
  15. GRB 990123, Field Photometry
  16. GRB 990217 Optical Observations
  17. GRB 990217, radio observations
  18. Optical Observations of GRB990217
  19. GRB990123: Caltech STIS Photometry and Images
  20. GRB990123 observations
  21. GRB990123, Optical Observation
  22. GRB 990123: Discovery of the Probable Host Galaxy
  23. GRB 990123: Reduced HST Images
  24. For Immediate Posting to GCN - HST Data GRB 990123 Available
  25. GRB19990123 observations
  26. GRB 990123: BVRI standards in the field
  27. GRB 990123: Updated Keck Spectroscopy Results
  28. GRB981220, field photometry
  29. GRB 990123 NOT Spectrum Update
  30. GRB990123, Optical observation
  31. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  32. GRB 990123: Publicly available reduced HST images
  33. GRB990123, Upcoming HST Service Observations
  34. GRB 990123: New Constraints on Possible Foreground Galaxies
  35. GRB990123 Optical Observations
  36. GRB990123, Probability of gravitational lensing
  37. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  38. GRB 990123: Continued Radio Observations
  39. GRB990123, Preliminary Lens Search Results
  40. GRB 990123: Correction to GCN 230 - C.A. Young added to author list
  41. On the Lensing Interpretation of GRB 990123
  42. Search for Potential Images of GRB 990123
  43. Search for Potential Images of GRB 990123
  44. GRB990123, Optical BVRI Observations
  45. GRB 990123: near-infrared observations.
  46. GRB990123, OSSE observations
  47. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  48. "GRB 990123: New BV Observations"
  49. GRB 990123 Optical Follow-Up
  50. GRB 990123; Addendum to GCN 223
  51. GRB 990123: BATSE Observations
  52. GRB 990123 Keck Spectrum update
  53. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  54. GRB990123 Optical Observations
  55. GRB 990123 Spectroscopic Redshifts
  56. GRB 990123: New Optical Observations, Decay Measure
  57. GRB 990123 Optical Follow-Up
  58. GRB 990123: Possible Gravitationally Lensed Burst?
  59. GRB 990123 optical observations
  60. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  61. GRB 990123 radio observations
  62. GRB 990123, new radio source
  63. GRB990123, Optical observation
  64. GRB 990123: Optical Decay Slope
  65. GRB 990123 r-band photometry
  66. GRB 990123 Optical Follow-up
  67. GRB990123, early optical counterpart detection
  68. GRB990123 Optical Observation
  69. GRB 990123: Bright New Source, Possible Optical Transient
  70. GRB 990123, Radio observations
  71. SN 1999E & GRB 980919
  72. Possible identification of SN1999E with GRB980910
  73. Optical Observations of GRB 981220
  74. GRB 981226: radio variable
  75. GRB981220
  76. GRB981220, Optical Observations
  77. GRB 981220 Optical observations
  78. GRB 981226 Optical Observations
  79. GRB 980613: Spectroscopy of the host galaxy
  80. GRB981226, sub-millimeter observations
  81. GRB981220, sub-millimeter observations
  82. GRB 981220 and GRB 981226, optical observations
  83. GRB 981226 radio observations
  84. GRB 981226
  85. GRB 981226 optical observations
  86. radio observations of GRB 981226
  87. GRB981220 B, R and I band observations
  88. GRB 981220:Optical Observations
  89. GRB 981220 optical R and I observations
  90. GRB981226, BeppoSAX Christmas GRB
  91. GRB 981226 - Infrared Observations
  92. GRB 981226 optical observations
  93. GRB 981220
  94. GRB 981220, radio observations
  95. GRB981226 Optical Observation
  96. GRB 981220, radio observations
  97. GRB 981220: BeppoSAX/GRBM results
  98. GRB981220 I-band Observations
  99. GRB 981220
  100. GRB 981220 Optical Observations

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