Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! See news and announcements

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"

45420 results found.

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

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov