Skip to main content
New Announcement Feature, Code of Conduct, Circular Revisions. 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').

22242 results found.

  1. GRB 990123: Reduced HST Images
  2. GRB19990123 observations
  3. GRB 990123: BVRI standards in the field
  4. GRB981220, field photometry
  5. GRB990123, Optical observation
  6. GRB990123, 15-GHz limits
  7. GRB 990123: New Constraints on Possible Foreground Galaxies
  8. GRB990123 Optical Observations
  9. GRB990123, Probability of gravitational lensing
  10. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  11. GRB990123, Preliminary Lens Search Results
  12. On the Lensing Interpretation of GRB 990123
  13. Search for Potential Images of GRB 990123
  14. Search for Potential Images of GRB 990123
  15. GRB990123, Optical BVRI Observations
  16. GRB 990123: near-infrared observations.
  17. GRB990123, OSSE observations
  18. GRB990123: NIR Observation
  19. GRB990123, ASCA X-ray observation of afterglow
  20. "GRB 990123: New BV Observations"
  21. GRB 990123 Optical Follow-Up
  22. GRB 990123: BATSE Observations
  23. GRB990123 Optical Observations
  24. GRB 990123: New Optical Observations, Decay Measure
  25. GRB 990123 Optical Follow-Up
  26. GRB 990123: Possible Gravitationally Lensed Burst?
  27. GRB990123, optical observation
  28. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  29. GRB990123, Optical observation
  30. GRB 990123: Optical Decay Slope
  31. GRB 990123 r-band photometry
  32. GRB 990123 Optical Follow-up
  33. GRB990123, early optical counterpart detection
  34. GRB990123 Optical Observation
  35. Possible identification of SN1999E with GRB980910
  36. Optical Observations of GRB 981220
  37. GRB 981226: radio variable
  38. GRB981220
  39. GRB981220, Correction to GCN 179
  40. GRB 981220 Optical observations
  41. GRB 981226 Optical Observations
  42. GRB 981220 and GRB 981226, optical observations
  43. GRB981226 Optical Observations
  44. GRB981226 BeppoSAX follow up
  45. GRB 981226
  46. GRB 981226 optical observations
  47. GRB981220 B, R and I band observations
  48. Optical Observations of GRB981226
  49. GRB 981220:Optical Observations
  50. GRB 981226 optical observations
  51. GRB 981220
  52. GRB 981220, radio observations
  53. GRB981220 I-band Observations
  54. GRB 981220
  55. GRB 980326/Host Galaxy
  56. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  57. BeppoSAX NFI Observation of GRB980425
  58. GRB980329 R,I flux calibration and R,I,K upper limits
  59. GRB980425 Optical Follow-up
  60. GRB 980923 BATSE Observations
  61. SGR1900+14, BeppoSAX-GRBM observations
  62. GRB970508 optical observations
  63. GRB971214, association with a Galactic star?
  64. GRB980519, Optical Observations
  65. GRB980703 - BeppoSAX/GRBM detection
  66. GRB980703 optical photometry
  67. GRB 980703: BATSE Observations
  68. GRB980703 optical observations
  69. GRB980703: Radio transient
  70. GRB 980703: Spectrum of the proposed optical counterpart
  71. GRB980703 Transient Optical Follow-Up
  72. GRB980703: LOTIS observation at early times
  73. GRB980613 Optical Observations
  74. GRB980703 (I band observations)
  75. BeppoSAX NFI observations of GRB 980703
  76. GRB980519 observation report
  77. GRB980703 optical followup
  78. Radio observations of SGRs
  79. SGR1900+14 field optical observations
  80. GRB980613, optical observations
  81. GRB 980613: Optical transient and its host galaxy
  82. SGR1627-41, RXTE/ASM observations
  83. GRB 980613: Detection of the probable host galaxy
  84. Reduced error box of SGR 1627-41
  85. GRB 980613: BATSE Observations
  86. GRB 980613 Optical Observations
  87. GRB 980613 optical observations
  88. Discovery of a new SGR source, SGR1627-41
  89. GRB980613 Optical Observations
  90. GRB980613 observations from Palomar
  91. GRB 980613 optical/IR obs.
  92. GRB980613 Near Infra-Red Observations
  93. GRB971214 Secondary Standards
  94. GRB980519 Secondary Standards
  95. BATSE on-board GRB trigger change
  96. GRB 980519 Optical Observations
  97. GRB 980519
  98. GRB980519 optical observations
  99. GRB 980519 Optical Observations
  100. GRB980519 BATSE Observations

Advanced

Download all Circulars as a .tar.gz archive:
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