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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"

45417 results found.

  1. GRB990510
  2. GRB 990510 optical observations
  3. GRB 990510 optical observations
  4. Galactic extinction towards GRB 990510
  5. GRB990510: NFI X-ray source
  6. GRB 990510 optical observations
  7. IPN localization of GRB990510
  8. GRB 990506 Radio Observations
  9. GRB 990123, optical monitoring
  10. GRB 990506: BATSE Observations
  11. GRB 990506, optical observations
  12. GRB 990510: Final BeppoSAX-WFC Coordinates
  13. GRB 990506, Optical Observations
  14. GRB 990506 optical observations
  15. GRB 990506 optical observations
  16. GRB 990506, optical observations
  17. GRB990506 observation plan
  18. Refined IPN error box for GRB990506
  19. GRB 990506: Limits on the possible optical transient
  20. GRB 990506, armchair astronomy
  21. GRB 990506, optical observations from +1 to +3 hours
  22. GRB 990506, optical observations
  23. GRB990506 Optical observations
  24. New IPN/RXTE error box for GRB990506
  25. IPN localization for GRB990506
  26. GRB 970228: Redshift and properties of the host galaxy
  27. IPN localization of GRB990427
  28. GRB981220 VLBA observations
  29. GRB980425 Optical observations of exponential decline at late time
  30. GRB990321 REFINED IPN ANNULUS
  31. GRB990323 PRECISE IPN POSITION
  32. GRB990321 IPN TRIANGULATION
  33. GRB 990316 Optical Observations
  34. GRB 990316, Radio observations
  35. GRB 990316, Optical observations
  36. GRB990316, Optical observations
  37. GRB 990316 optical observations
  38. GRB990316: simultaneous optical observation
  39. GRB990316 - Optical null results
  40. ASM/IPN error box for GRB 990308 (BATSE #7457)
  41. GRB990308 not a new SGR
  42. GRB 990308a and GRB 990308b
  43. GRB990308 (Trig. 7457), optical observations
  44. GRB990308, Possible new SGR~0209+70
  45. GRB981220, IPN localization
  46. GRB 981220, radio observations
  47. GRB 990123, Field Photometry
  48. GRB 990217 Optical Observations
  49. GRB 990217, radio observations
  50. BATSE Resumes Normal Operations
  51. GRB990217: BeppoSAX/GRBM data
  52. Optical Observations of GRB990217
  53. GRB990123: Caltech STIS Photometry and Images
  54. GRB990123 observations
  55. GRB990217, WFC position
  56. GRB990123, Optical Observation
  57. GRB 990123: Discovery of the Probable Host Galaxy
  58. GRB 990123: Reduced HST Images
  59. For Immediate Posting to GCN - HST Data GRB 990123 Available
  60. GRB19990123 observations
  61. GRB 990123: BVRI standards in the field
  62. GRB 990123: Updated Keck Spectroscopy Results
  63. GRB981220, field photometry
  64. GRB 990123 NOT Spectrum Update
  65. GRB990123, Optical observation
  66. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  67. GRB 990123: Publicly available reduced HST images
  68. GRB990123, Upcoming HST Service Observations
  69. GRB990123, 15-GHz limits
  70. GRB 990123: New Constraints on Possible Foreground Galaxies
  71. GRB990123 Optical Observations
  72. GRB990123, Probability of gravitational lensing
  73. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  74. GRB 990123: Continued Radio Observations
  75. GRB990123, Preliminary Lens Search Results
  76. GRB 990123: Correction to GCN 230 - C.A. Young added to author list
  77. On the Lensing Interpretation of GRB 990123
  78. Search for Potential Images of GRB 990123
  79. Search for Potential Images of GRB 990123
  80. GRB990123, Optical BVRI Observations
  81. GRB 990123: near-infrared observations.
  82. GRB990123, OSSE observations
  83. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  84. GRB990123: NIR Observation
  85. GRB990123, ASCA X-ray observation of afterglow
  86. "GRB 990123: New BV Observations"
  87. GRB 990123 Optical Follow-Up
  88. GRB 990123; Addendum to GCN 223
  89. GRB 990123: BATSE Observations
  90. GRB 990123 Keck Spectrum update
  91. GRB990123 IPN annulus
  92. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  93. GRB990123 Optical Observations
  94. GRB 990123 Spectroscopic Redshifts
  95. GRB 990123: New Optical Observations, Decay Measure
  96. GRB 990123 Optical Follow-Up
  97. GRB 990123: Possible Gravitationally Lensed Burst?
  98. GRB990123, optical observation
  99. GRB 990123 optical observations
  100. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy

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Download all Circulars as a .tar.gz archive (updated once a day):
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