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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"

44096 results found.

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

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