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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"
  1. GRB 981220, radio observations
  2. GRB 990123, Field Photometry
  3. GRB 990217 Optical Observations
  4. GRB 990217, radio observations
  5. BATSE Resumes Normal Operations
  6. BATSE Flight Anomaly
  7. GRB990217: BeppoSAX/GRBM data
  8. Optical Observations of GRB990217
  9. GRB990123: Caltech STIS Photometry and Images
  10. GRB990123 observations
  11. GRB990217 Optical observation
  12. GRB990217, WFC position
  13. GRB990123, Optical Observation
  14. GRB 990123: Discovery of the Probable Host Galaxy
  15. GRB 990123: Reduced HST Images
  16. For Immediate Posting to GCN - HST Data GRB 990123 Available
  17. GRB19990123 observations
  18. GRB 990123: BVRI standards in the field
  19. GRB 990123: Updated Keck Spectroscopy Results
  20. GRB981220, field photometry
  21. GRB 990123 NOT Spectrum Update
  22. GRB990123, Optical observation
  23. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  24. GRB 990123: Publicly available reduced HST images
  25. GRB990123, Upcoming HST Service Observations
  26. GRB990123, 15-GHz limits
  27. GRB 990123: New Constraints on Possible Foreground Galaxies
  28. GRB990123 Optical Observations
  29. GRB990123, Probability of gravitational lensing
  30. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  31. GRB 990123: Continued Radio Observations
  32. GRB990123, Preliminary Lens Search Results
  33. GRB 990123: Correction to GCN 230 - C.A. Young added to author list
  34. On the Lensing Interpretation of GRB 990123
  35. Search for Potential Images of GRB 990123
  36. Search for Potential Images of GRB 990123
  37. GRB990123, Optical BVRI Observations
  38. GRB 990123: near-infrared observations.
  39. GRB990123, OSSE observations
  40. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  41. GRB990123: NIR Observation
  42. GRB990123, ASCA X-ray observation of afterglow
  43. "GRB 990123: New BV Observations"
  44. GRB 990123 Optical Follow-Up
  45. GRB 990123; Addendum to GCN 223
  46. GRB 990123: BATSE Observations
  47. GRB 990123 Keck Spectrum update
  48. GRB990123 IPN annulus
  49. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  50. GRB990123 Optical Observations
  51. GRB 990123 Spectroscopic Redshifts
  52. GRB 990123: New Optical Observations, Decay Measure
  53. GRB 990123 Optical Follow-Up
  54. GRB 990123: Possible Gravitationally Lensed Burst?
  55. GRB990123, optical observation
  56. GRB 990123 optical observations
  57. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  58. GRB 990123 radio observations
  59. GRB 990123, new radio source
  60. GRB990123 optical observations
  61. GRB990123, Optical observation
  62. GRB 990123: Optical Decay Slope
  63. GRB 990123 r-band photometry
  64. GRB 990123 Optical Follow-up
  65. GRB990123, early optical counterpart detection
  66. GRB990123 Optical Observation
  67. GRB990123, BeppoSAX-NFI X-ray afterglow detection
  68. GRB990123, refined SAX-WFC position
  69. GRB 990123: Bright New Source, Possible Optical Transient
  70. GRB 990123, Radio observations
  71. GRB990123, BeppoSAX WFC detection and NFI planned follow-up
  72. SN 1999E & GRB 980919
  73. Possible identification of SN1999E with GRB980910
  74. Optical Observations of GRB 981220
  75. GRB 981226: radio variable
  76. GRB981220
  77. GRB981220, Correction to GCN 179
  78. GRB981220, Optical Observations
  79. GRB 981220 Optical observations
  80. GRB 981226 Optical Observations
  81. GRB 980613: Spectroscopy of the host galaxy
  82. GRB981226, sub-millimeter observations
  83. GRB981220, sub-millimeter observations
  84. GRB 981220 and GRB 981226, optical observations
  85. GRB981226 Optical Observations
  86. GRB981226 BeppoSAX follow up
  87. GRB 981226 radio observations
  88. GRB 981226
  89. GRB 981226 optical observations
  90. radio observations of GRB 981226
  91. GRB981220 B, R and I band observations
  92. GRB981226, BeppoSAX-NFI follow-up
  93. Optical Observations of GRB981226
  94. GRB 981220:Optical Observations
  95. GRB 981220 optical R and I observations
  96. GRB981226, BeppoSAX Christmas GRB
  97. GRB 981226 - Infrared Observations
  98. GRB 981226 optical observations
  99. GRB 981220
  100. GRB 981220, radio observations

Advanced

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