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"

45500 results found.

  1. XRF040701: Optical Observations at ESO
  2. IPN/HETE triangulation of GRB040802 (=H3485)
  3. GRB 040730, infrared observations
  4. GRB 040730: Optical observations
  5. GRB 040730: a long GRB detected with INTEGRAL
  6. Ongoing activity of SGR 1806-20
  7. GRB040624: optical monitoring at TNG
  8. XRF 040701 - optical observations of the decaying Chandra source
  9. XRF040701: Second-Epoch Chandra Observations
  10. Cancellation of IBAS/INTEGRAL GRB alerts
  11. XRF040701: VLA Observations
  12. XRF040701: Magellan Spectroscopy of Chandra Source #2 Associated Galaxy
  13. XRF040701: First-Epoch Chandra Observations
  14. IBAS Alert 1836: NOT a real GRB
  15. GRB040709 J,H-band observations
  16. GRB040624, optical observations
  17. GRB040706:observation at University of Miyazaki
  18. XRF 040701, optical observations
  19. XRF040701 (=U11548): a bright XRF detected by HETE
  20. GRB 040624: optical observations
  21. Optical Observations of GRB040624
  22. GRB 040624: optical observations at TNG and VLT
  23. MASTER: GRB 040624 optical observation after 0,48d
  24. GRB 040624: R-band observations
  25. GRB 040624, optical observations
  26. GRB 040624 - A long GRB detected with INTEGRAL
  27. GRB 030329: Rebrightening of hyperluminal ejecta.
  28. IPN Summary of SGR1806-20 Activity in 2004
  29. GRB040511: Retraction of redshift identification
  30. SGR 1806-20: no IR variability of the proposed counterparts
  31. MASTER:HETE Alert 3259 (SRG1806-20) optical observation
  32. SGR 1806-20, potential NIR counterpart
  33. GRB 040606: Optical observations
  34. MASTER: HETE Alert 3274 optical observation
  35. Activivty of SGR 1806-20
  36. IPN triangulation of an intense intermediate burst from SGR1806-20
  37. GRB 040511, very fast decay?
  38. GRB 030324: Detection and Color of Host Galaxy
  39. GRB 040511: NIR observations with REM
  40. GRB040511: Redshift identifcation
  41. GRB 040511: Optical limit
  42. GRB040511: Candidate optical/NIR afterglow
  43. IBAS GRB Alerts n.1785 to 1791
  44. GRB 040511: ROTSE-III Rapid Optical Upper Limits
  45. GRB 040511: Second Epoch Optical Observations
  46. GRB 040511: Optical observations
  47. GRB 040511: Optical Observations
  48. GRB040511: Optical Observations
  49. GRB040511: Optical Observations
  50. GRB040511 (=H3218): A Long GRB Localized by HETE WXM and SXC
  51. IBAS GRB Alert number 1774: NOT a real GRB
  52. Type Ic SN2001em (off-axis GRB jet?), optical spectrum
  53. IBAS Alerts 1771 and 1772: NOT a real GRB
  54. GRB and XRF on April 27, 2004. Detection by Konus-Wind and Helicon (Coronas-F)
  55. IPN triangulation of GRB040425 (=H3183)
  56. On Line Availability of Archival HETE Fregate Data and Lightcurves
  57. GRB040422: optical observations at Xinglong Observatory
  58. GRB040422: optical observations at CrAO
  59. GRB 040423 (=H3175): A Long GRB Localized by HETE
  60. GRB040422, optical observations at Loiano
  61. GRB040422 : I-band follow-up observation at Lulin Observatory
  62. GRB 040422: ROTSE-IIIb Prompt Optical Limits
  63. GRB040422, BVRcIc field calibration
  64. GRB 040422,optical observation
  65. GRB040422: optical and NIR observations at the VLT
  66. GRB 040422: a long GRB detected with INTEGRAL
  67. GRB 040403, deep optical observations
  68. MASTER: HETE Alert 3163, 3167 technical optical observation
  69. INTEGRAL-SPI/ACS GRB data: timing correction
  70. IBAS GRB alerts 1739, 1740, 1741
  71. HETE/IPN localization of GRB040403A (=H3143, a long burst) and GRB040403B(=H3144, a short/hard burst)
  72. GRB 040403: Optical Observations
  73. GRB 040403 Optical Observations
  74. GRB 040403: Optical observations
  75. GRB 040403: optical observations
  76. GRB 040403: Optical Observations
  77. GRB 040403: a long GRB detected with INTEGRAL
  78. Summary of recent bursts from SGR 1806-20 detected by INTEGRAL
  79. GRB 040329: hard burst detected by Konus-Wind and Helicon - Coronas-F
  80. IBAS GRB Alert 1694
  81. GRB040323: NIR Observations and Variable Object
  82. GRB 040319 (=H3128): An X-Ray-Rich GRB Localized by the HETE-2 WXM and SXC
  83. GRB 040323, a dark GRB ?
  84. short hard GRB 040322
  85. GRB 040323: a long GRB detected with INTEGRAL
  86. IBAS GRB alerts 1679, 1680, 1681
  87. GRB040223: Deep NIR NTT data re-analysis
  88. GRB 040223: XMM-Newton results
  89. GRB040223, improved XMM position
  90. IBAS Alert 1678: not a GRB
  91. GRB 031203: spectoscopic evidence for a 1998bw-like SN
  92. GRB 031203, possible supernova
  93. MASTER: RXTE GRB040308 optical observation
  94. IBAS results on a burst from SGR1806-20
  95. INTEGRAL detection of activity from SGR1806-20
  96. RXTE GRB040229 optical observation: no candidate
  97. GRB 040228 Optical observations
  98. IPN triangulation of GRB040228 (H3066, H3067)
  99. GRB040228 : KISO optical follow-up observation
  100. GRB 040228 (=H3066?,=H3067?): A Long GRB Localized by the HETE-2 WXM

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