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').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
307 results found.
- GRB 181201A: a long GRB detected by INTEGRAL
- GRB 180809A: further Swift/XRT observations
- GRB 180728A: VLT/X-shooter redshift of a nearby energetic GRB
- LIGO/Virgo G298048: Chandra X-ray Update on GW170817
- LIGO/Virgo G298048: Discovery of X-ray emission from SSS17a in NGC4993
- LIGO/Virgo G298936: Astrosat CZTI upper limits
- LIGO/Virgo G298048: INTEGRAL pointed follow-up observations
- LIGO/Virgo G298048: Chandra X-ray observations
- GRB170730A detecetd by INTEGRAL. Refined analysis
- LIGO/Virgo G268556/GW170104: Lomonosov BDRG observations
- Swift-BAT refined analysis of the recent outburst from SGR 1617-5103 (a.k.a. 1E 161348-5055 and 2E 1613.5-5053)
- GRB 160401A: a long GRB detected by INTEGRAL
- LIGO/Virgo G184098: Fermi-GBM ground-based follow-up
- GRB 150912A: A long GRB detected by INTEGRAL
- SGR 1E 1841-045 (Swift trigger 649113): Terskol upper limit
- Fermi GBM triggers bn150715759 and bn150715817 are not due to GRBs
- Trigger 649113: Swift detection of SGR 1E 1841-045
- Swift trigger 642453 is not an astrophysical source
- GRB 140710B: a long GRB detected with INTEGRAL
- GRB 140705A / SGR 1935+2154: Probable association with supernova remnant G57.2+0.8
- Swift detection of a bright X-ray source in M31
- GRB 131108A: AGILE/GRID observation
- Observation of possible GRB/TDE 130925A by INTEGRAL/SPI-ACS: three activity episodes
- GRB 130907A: INTEGRAL/SPI-ACS light curve
- GRB 130513A: a long GRB detected by INTEGRAL
- Swift-BAT refined analysis of SGR 1E 1841-045 (Trigger=543763)
- Trigger 543763: SGR 1E 1841-045: Swift detection of a soft gamma repeater burst (aka Kes 73)
- GRB 121102A : a long GRB detected by INTEGRAL
- GRB 121027A: Swift-XRT refined Analysis
- Swift-BAT refined analysis of 1E 1841-045 (Trigger=526660)
- Trigger 526660: Swift detection of 1 E 1841-045 (aka Kes 73)
- GRB 120624B: Swift-XRT observations
- GRB 120512A: A long GRB detected by INTEGRAL
- Fermi/GBM detection of a burst from the magnetar 1E 2259+5
- Swift J1822.3-1606: Transient Magnetar or Be X-ray Binary?
- SGR 1E 1841-045: early optical limit by "Pi of the Sky"
- SGR 1E 1841-045: Swift-BAT refined analysis
- SGR 1E 1841-045: Swift detection of a soft gamma repeater burst
- GRB 110625A: Fermi GBM and LAT observations
- SGR 1E 1841-045: Swift-BAT refined analysis
- SGR 1E 1841-045: Swift detection of a soft gamma repeater burst
- ICSP VLF observation of multiple SGR-like bursts from 1E 1841-045 on Feb. 9, 2011
- Fermi GBM detection of an SGR-like burst
- Swift-BAT refined analysis of outburst from 1E 1841-04.5
- Fermi GBM detection of a burst from 1E 1841-045
- SGR-like outburst from the magnetar 1E 1841-04.5
- GRB 110112B: A short GRB detected by INTEGRAL
- An SGR-like burst from the magnetar 1E 1841-04.5 in Kes 73
- GRB 100316D: Pre-burst emission measured by BAT
- GRB 090709A: Quasiperiodic variations in the BAT light curve
- XRF 090702: Swift-XRT refined analysis
- A bright burst from AXP 1E 1547.0-5408/SGR J1550-5418
- SGR J1550-5418
- IBAS Alert N. 5442 is not a GRB
- Suzaku ToO Observation of AXP 1E 1547.0-5408
- Konus-Wind observation of AXP/SGR 1E1547.0-5408 bursting activity
- GRB 081222: Swift XRT refined analysis
- INTEGRAL ToO observation of the AXP 1E 1547.0-5408
- AXP 1E 1547.0-5408: Swift/UVOT Upper Limits
- GRB080818B: GLAST Burst Monitor detection
- GRB 080520: Swift XRT Refined Analysis
- GRB 080205: Swift XRT refined analysis
- GRB 080121: Upper limit on X-ray afterglow
- GRB080120: Swift XRT position
- Swift XRT follow-up observations of GRB071008
- GRB 071003: XRT refined analysis
- GRB 070729: Swift-XRT refined analysis
- GRB 070520B: Swift-XRT refined analysis
- GRB 070520A: Swift-XRT refined analysis
- GRB070224: Swift-XRT Refined Analysis
- GRB070107: Swift/XRT refined analysis
- Retractions of previous Swift-BAT triggers
- GRB061222B: Swift-XRT Refined Analysis
- GRB061025: Swift XRT refined analysis
- IGR J08408-4503 (= V* LM Vel): Swift detection of a transient
- GRB 060729: An update on the late-time Swift observations
- GRB 060926: Swift XRT refined analysis
- Two bright bursts from SGR 1806-20 detected with IBAS
- GRB060213: Swift XRT observations and possible afterglow candidate
- GRB060204a: Swift XRT Detection of an Afterglow Candidate
- Swift XRT Observation of GRB 060204C
- GRB060203: Swift XRT Team Refined Analysis
- Possible GRB 050922 detected by INTEGRAL
- GRB 050716: Refined XRT analysis.
- GRB 050509B: Swift/XRT refined analysis
- GRB 050502 - A long GRB detected with INTEGRAL
- SGR 1806-20, RHESSI observations of the 041227 giant flare
- GRB041220: Swift-BAT burst
- Swift-BAT detection of the bright long burst GRB041219
- GRB 041219 - A long GRB detected by INTEGRAL
- XMM-Newton Images of GRB 040827
- XRF040701: Second-Epoch Chandra Observations
- XRF040701: First-Epoch Chandra Observations
- GRB040511 (=H3218): A Long GRB Localized by HETE WXM and SXC
- GRBlog: Compilation of all GCN Circ. data
- IPN detection of renewed activity from SGR1806-20
- IPN triangulation of GRB021119 (annulus)
- IPN triangulation of GRB021025 (annulus)
- Gemini IR Detection of AXP 1E 2259+586 Post-Burst
- SGR-like X-ray Bursts from AXP 1E 2259+586: follow-up