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This tweet from India's prime minister Narendra Modi says:

मेरे प्यारे देशवासियों,

आज सवेरे लगभग 11.45 - 12.00 बजे मैं एक महत्वपूर्ण संदेश लेकर आप के बीच आऊँगा।

I would be addressing the nation at around 11:45 AM - 12.00 noon with an important message.

Do watch the address on television, radio or social media.

There are several subsequent tweets with more specifics, including this one:

In the journey of every nation there are moments that bring utmost pride and have a historic impact on generations to come.

One such moment is today.

India has successfully tested the Anti-Satellite (ASAT) Missile. Congratulations to everyone on the success of #MissionShakti.

Question: At what range of altitudes is the resulting debris field?

note: I'm not asking for just a guess or speculation, please include a source of some type.

YouTube: DRDO's Anti Satellite (A-SAT) Test Visuals

From Times of India's Watch: Launch of anti-satellite missile for Mission Shakti:

The apogee/ perigee of 2019-006A, the object likely shot down, was 260- 282 km, pretty low. Some of that debris could be quite a bit higher, but most of it will be lower, and all of it will have a new perigee/ apogee in that range, which will likely be shrinking quickly. It is expected that it will be similar to the debris cloud from USA-193 (Operation Burnt Frost), which had the following debris cloud Gabbard Plot (From Celestrak). Note that all debris reentered within 18 months after that operation, and most within a few days. I suspect it won't be quite as energetic, as there presumably isn't as much fuel quick could cause a significant energy event, but it's the best we have for now.

The best place to look would be from Space-Track's new catalog objects not associated with a launch. That data should be available soon. If you want to follow someone on Twitter to find out more, I recommend Jonathan McDowell

At this time, it is not yet known. There are some 250 objects observed, but it takes time to catalog them all. The object destroyed was most likely MICROSAT-R (TLE catalog number 43947, which is in a 294 x 265 km orbit at 96 degrees inclination.

Due to the nature of the event, it's likely some of the objects have apogees well above ISS orbit. At this time, there is little to no public data available. When it comes available, you can expect to see it at space-track.org and celestrak.org in addition to the twitter account @TSKelso.

I'll just follow up a bit on the collision.

Per tweet and tweet and answer and answer and post:

• launch 5:40 UT (27 March 2019)


• MICROSAT-r 43947, 2019-006A


• over Abdul Kalam Island 5:42 UT

I've put a recent TLE into Skyfield and we can see that the satellite was moving north from the equator towards Abdul Kalam Island, India. According to the image in India's surprise ASAT test of 27 March 2019 the launch was somewhat south over the ocean to meet it.

At 05:42 the altitude was about 281 km and the velocity 7.73 km/s.

MICROSAT-R 
1 43947U 19006A 19086.74388517 .07448791 20151+0 12875-1 0 9992
2 43947 96.7526 0.1883 0022976 252.9519 167.8627 16.09438738 9918

Source

# https://celestrak.com/satcat/
TLE = """MICROSAT-R 
1 43947U 19006A 19086.74388517 .07448791 20151+0 12875-1 0 9992
2 43947 96.7526 0.1883 0022976 252.9519 167.8627 16.09438738 9918"""
name, L1, L2 = TLE.splitlines()

# https://twitter.com/DutchSpace/status/1110833431523545088
# https://twitter.com/Marco_Langbroek/status/1110861054010105858
# https://sattrackcam.blogspot.com/2019/03/indias-surprise-asat-test-of-27-march.html
# launch 5:40 UT (27 March 2019)
# over 5:42 UT on 27 March 2019
# Abdul Kalam island on the Indian East Coast
# 20.757N, 87.084E

import numpy as np
import matplotlib.pyplot as plt
from skyfield.api import Topos, Loader, EarthSatellite

load = Loader('~/Documents/fishing/SkyData') # single instance for big files
ts = load.timescale()
de421 = load('de421.bsp')
earth = de421['earth']

Abdul_Kalam_Island = earth + Topos(latitude_degrees = +20.757,
 longitude_degrees = +87.084,
 elevation_m = 10.0)
minutes = np.arange(35, 50, 0.1)
times = ts.utc(2019, 3, 27, 5, minutes)

MICROSAT_r = earth + EarthSatellite(L1, L2)

astrometric = Abdul_Kalam_Island.at(times).observe(MICROSAT_r)
alt, az, d = astrometric.apparent().altaz(pressure_mbar=0)

pos_42 = earth.at(ts.utc(2019, 3, 27, 5, 42)).observe(MICROSAT_r).position.km
vel_42 = earth.at(ts.utc(2019, 3, 27, 5, 42)).observe(MICROSAT_r).velocity.km_per_s

r = np.sqrt((pos_42**2).sum())
v = np.sqrt((vel_42**2).sum())
print pos_42
print r
print r - 6378.137
print v

if True:
 plt.figure()
 plt.subplot(3, 1, 1)
 plt.plot(minutes, alt.degrees)
 plt.ylabel('elevation (deg)', fontsize=16)
 plt.ylim(0, 90)
 plt.xlim(35, 50)

 plt.subplot(3, 1, 2)
 plt.plot(minutes, az.degrees)
 plt.ylabel('azimuth (deg)', fontsize=16)
 plt.ylim(0, 360)
 plt.xlim(35, 50)

 plt.subplot(3, 1, 3)
 plt.plot(minutes, d.km)
 plt.ylabel('range (km)', fontsize=16)
 plt.xlabel('time after 05:00 (minutes)', fontsize=16)
 plt.ylim(250, 500)
 plt.xlim(35, 50)

 plt.suptitle('MICROSAT-r vs Abdul Kalam Island, 27-03-2019 UTC', fontsize=16)
 plt.show()