Skip to main content
JSON Notices via Email, Kafka Cron Jobs, Submitter Profile, GCN is Hiring. See news and announcements

GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

16119 results found.

  1. EP241217a: Gemini-North spectroscopic redshift z = 4.59
  2. EP241217a: Kinder optical follow-up observations
  3. EP241217A: LCO optical observations
  4. EP241217a: Gemini-North detection of the likely optical counterpart
  5. GRB 241215A: Mondy AZT-33IK optical observations
  6. GRB 241215A: Nanshan/HMT optical upper limit
  7. GRB 241215A: Montarrenti Observatory optical upper limit
  8. GRB 241215A: GROWTH-India telescope optical upper limit
  9. GRB 241209B: SVOM/VT optical continuous fading
  10. GRB 241213A: SVOM/VT optical candidate
  11. GRB 241213A: Swift/UVOT Upper Limits
  12. GRB 241212A: Fermi GBM detection
  13. EP241208a: NOT optical upper limits
  14. GRB 241213A: LCOGT Optical Upper Limits
  15. GRB 241213A: REM optical/NIR upper limits
  16. GRB241212A: OHP/T193 optical observations
  17. GRB 241213A: SAO RAS optical upper limit
  18. GRB 241212A : SVOM/C-GFT optical upper limit at early phase
  19. GRB 241212A : SVOM/VT bright optical afterglow
  20. GRB 241209B: GRANDMA/TRT upper limit
  21. GRB 241207A: TSHAO Zeiss-1000 optical observations
  22. GRB 241212A: SVOM detection of a bright long burst
  23. GRB 241209B: Mondy AZT-33IK and AbAO AS-32 optical observations
  24. GRB 241209D: REM optical/NIR upper limits
  25. GRB 241209B: Swift-XRT afterglow detection
  26. EP241208a: Optical upper limit with Kinder observations
  27. GRB 241128A: CrAO ZTSh and Mondy AZT-33IK optical observations
  28. GRB 241209B: SVOM/VT afterglow detection
  29. GRB 241209A: BOOTES-7 and 2.2m CAHA early optical upper limits
  30. GRB 241209D: COLIBRÍ detection of the afterglow
  31. GRB 241209A: COLIBRÍ Optical Upper Limit
  32. GRB 241209A: Fermi GBM Observation
  33. GRB 241209A: GRANDMA/TAROT upper limit
  34. GRB 241209B: BOOTES-5 optical upper limit
  35. LIGO/Virgo/KAGRA S241102br: continued GRAWITA observations and detection of an optical transient (AT2024adip)
  36. GRB 241209A: REM optical/NIR observations
  37. GRB 241209D: Swift detection of a burst
  38. GRB 241209A: VLT optical observations
  39. GRB 241209A: GOTO optical upper limits
  40. EP241206a: 1.5m OSN optical limit
  41. AT2024adec: X-ray Upper Limits from EP-FXT Observation
  42. EP241206a: BOOTES Global Network optical limits
  43. GRB 241207C: MASTER optical observations
  44. GRB 241206B: GWAC-F50A optical upper limit
  45. EP241113a: Keck/LRIS spectroscopic observation and tentative redshift
  46. EP241201a: 1.6m Mephisto Optical Upper Limits
  47. GRB 241204A: COLIBRÍ Optical Upper Limit
  48. EP241202b: KAIT optical upper limit
  49. EP241202b: Kinder optical counterpart candidate
  50. EP241201a: BOOTES-5 optical upper limit
  51. EP241201a: NOT optical observations
  52. GRB 241128A: Swift/UVOT Upper Limits
  53. EP241201a: Kinder optical counterpart candidate
  54. LIGO/Virgo/KAGRA S241102br: GRAWITA wide-field optical observations
  55. EP241126a: SOAR observations of the optical counterpart
  56. EP241126a: 1.6m Mephisto Optical Upper Limits
  57. LIGO/Virgo/KAGRA S241125n: GRANDMA Optical Upper Limits
  58. GRB 241128A: AbAO optical upper limit
  59. EP241126a: NOT optical observations
  60. GRB 241127A: PRIME near-infrared detection
  61. GRB 241128A: Mondy optical observations
  62. GRB 241128A: GRANDMA and Kilonova-Catcher Optical Afterglow Detections and Upperlimits
  63. Swift-XRT observations of IceCube -241127A
  64. EP241126a: SVOM/VT observations
  65. GRB 241128A: NOT optical observations
  66. GRB 241128A: LCO optical detection
  67. GRB 241128A: 1.5m OSN optical afterglow detection
  68. GRB 241127A: GRANDMA and Kilonova-Catcher optical afterglow detections
  69. GRB 241127A: Swift/UVOT Detection
  70. GRB 241127A: SVOM/GRM observation
  71. GRB 241127A: LCOGT (40-cm) optical counterpart detection
  72. Swift GRB241127.91: Global MASTER-Net OT detection
  73. EP241126a: WFST Observations
  74. GRB 241127A: Swift detection of a burst with an optical counterpart
  75. Swift GRB241127.91: Global MASTER-Net OT detection
  76. EP241126a: Optical Upper limits with Kinder observations
  77. EP trigger ID 01709122294: 1.6m Mephisto multi-band optical observations
  78. EP241126a: EP-FXT follow-up observation update
  79. EP241126a: GSP detects optical counterpart
  80. EP241126a: TRT optical counterpart detection
  81. LIGO/Virgo/KAGRA S241125n: COLIBRÍ Upper Limits on Optical Counterparts to Two of the Swift/XRT Sources
  82. GRB 241113B: EP-FXT afterglow detection
  83. LIGO/Virgo/KAGRA S241125n: DDOTI Optical Upper Limits
  84. LIGO/Virgo/KAGRA S241125n: Gaoyazi/GOT optical observations
  85. SVOM/GRM detection of a short burst from SGR 1830
  86. LIGO/VIRGO/KAGRA S241125n: GROWTH-India telescope optical observations
  87. GRB 241026A: radio detection with the VLA
  88. EP241125a: Optical upper limit with Kinder observations
  89. LIGO/Virgo/KAGRA S241125n: COLIBRÍ Upper Limits on a Optical Counterpart at the BAT Position
  90. LIGO/Virgo/KAGRA S241125n: Kinder optical upper limit in the BAT error region
  91. GRB 241113B: SVOM/VT optical afterglow observations
  92. GRB 241105A: ATCA radio detection
  93. GRB 241026A: VIRT Optical Upper Limit
  94. GRB 241025A: VIRT Optical Upper Limit
  95. GRB241120A: OHP/T193 optical observations
  96. EP241021a and EP241026b: Keck/LRIS spectroscopic observations
  97. EP trigger ID 01709065118: Keck/LRIS spectroscopic observations
  98. EP-WXT trigger 01709018832: Lick/Kast spectroscopy with the 3 m Shane telescope
  99. GRB 241120A: Mondy and AbAO optical observations
  100. EP241119a: Optical upper limits with Kinder observations

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