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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. IPN localization for GRB990506
  2. GRB 970228: Redshift and properties of the host galaxy
  3. IPN localization of GRB990427
  4. GRB981220 VLBA observations
  5. GRB980425 Optical observations of exponential decline at late time
  6. GRB990321 REFINED IPN ANNULUS
  7. GRB990323 PRECISE IPN POSITION
  8. GRB990321 IPN TRIANGULATION
  9. GRB 990316 Optical Observations
  10. GRB 990316, Radio observations
  11. GRB 990316, Optical observations
  12. GRB990316, Optical observations
  13. GRB 990316 optical observations
  14. GRB990316: simultaneous optical observation
  15. GRB990316 - Optical null results
  16. ASM/IPN error box for GRB 990308 (BATSE #7457)
  17. GRB990308 not a new SGR
  18. GRB 990308a and GRB 990308b
  19. GRB990308 (Trig. 7457), optical observations
  20. GRB990308, Possible new SGR~0209+70
  21. GRB981220, IPN localization
  22. GRB 981220, radio observations
  23. GRB 990123, Field Photometry
  24. GRB 990217 Optical Observations
  25. GRB 990217, radio observations
  26. BATSE Resumes Normal Operations
  27. BATSE Flight Anomaly
  28. GRB990217: BeppoSAX/GRBM data
  29. Optical Observations of GRB990217
  30. GRB990123: Caltech STIS Photometry and Images
  31. GRB990123 observations
  32. GRB990217 Optical observation
  33. GRB990217, WFC position
  34. GRB990123, Optical Observation
  35. GRB 990123: Discovery of the Probable Host Galaxy
  36. GRB 990123: Reduced HST Images
  37. For Immediate Posting to GCN - HST Data GRB 990123 Available
  38. GRB19990123 observations
  39. GRB 990123: BVRI standards in the field
  40. GRB 990123: Updated Keck Spectroscopy Results
  41. GRB981220, field photometry
  42. GRB 990123 NOT Spectrum Update
  43. GRB990123, Optical observation
  44. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  45. GRB 990123: Publicly available reduced HST images
  46. GRB990123, Upcoming HST Service Observations
  47. GRB990123, 15-GHz limits
  48. GRB 990123: New Constraints on Possible Foreground Galaxies
  49. GRB990123 Optical Observations
  50. GRB990123, Probability of gravitational lensing
  51. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  52. GRB 990123: Continued Radio Observations
  53. GRB990123, Preliminary Lens Search Results
  54. GRB 990123: Correction to GCN 230 - C.A. Young added to author list
  55. On the Lensing Interpretation of GRB 990123
  56. Search for Potential Images of GRB 990123
  57. Search for Potential Images of GRB 990123
  58. GRB990123, Optical BVRI Observations
  59. GRB 990123: near-infrared observations.
  60. GRB990123, OSSE observations
  61. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  62. GRB990123: NIR Observation
  63. GRB990123, ASCA X-ray observation of afterglow
  64. "GRB 990123: New BV Observations"
  65. GRB 990123 Optical Follow-Up
  66. GRB 990123; Addendum to GCN 223
  67. GRB 990123: BATSE Observations
  68. GRB 990123 Keck Spectrum update
  69. GRB990123 IPN annulus
  70. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  71. GRB990123 Optical Observations
  72. GRB 990123 Spectroscopic Redshifts
  73. GRB 990123: New Optical Observations, Decay Measure
  74. GRB 990123 Optical Follow-Up
  75. GRB 990123: Possible Gravitationally Lensed Burst?
  76. GRB990123, optical observation
  77. GRB 990123 optical observations
  78. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  79. GRB 990123 radio observations
  80. GRB 990123, new radio source
  81. GRB990123 optical observations
  82. GRB990123, Optical observation
  83. GRB 990123: Optical Decay Slope
  84. GRB 990123 r-band photometry
  85. GRB 990123 Optical Follow-up
  86. GRB990123, early optical counterpart detection
  87. GRB990123 Optical Observation
  88. GRB990123, BeppoSAX-NFI X-ray afterglow detection
  89. GRB990123, refined SAX-WFC position
  90. GRB 990123: Bright New Source, Possible Optical Transient
  91. GRB 990123, Radio observations
  92. GRB990123, BeppoSAX WFC detection and NFI planned follow-up
  93. SN 1999E & GRB 980919
  94. Possible identification of SN1999E with GRB980910
  95. Optical Observations of GRB 981220
  96. GRB 981226: radio variable
  97. GRB981220
  98. GRB981220, Correction to GCN 179
  99. GRB981220, Optical Observations
  100. GRB 981220 Optical observations

Advanced

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