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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"

45371 results found.

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

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